I will list the 8 current traits in the order that I believe are the strongest to the weakest and try to explain why. Keep in mind that I believe that Firaxis has done a decent job of balancing the traits, so just because i put one a few slots higher than the other doesn't mean that I think it's necessarily waaaaaaaay better. I'm also not trying to put down what I think the majority of people agree with. Being as objective as possible, I am attempting to weigh the benefits and possible applications of each to determine what I think is the strongest. It may be that I haven't had as much experience with some traits as others and therefore have not fully realized their potential. Feel free to make any suggestions with reguards to any advantage or dis-advantage that I may have (and probably have) missed. Also, any comments questions or suggestions are most welcome
1. Industrial:
-50% production bonus of wonders
-double production speed of forges
-Advantages: Industrial in my opinion is the strongest single trait in the game. The bonus for constructing wonders offers a great variety of possible strategies. It helps you to tailor make a strategy based on the type of wonders you go for. The wonder bonus also enables you to simulate some of the other traits such as creative from building stonehenge, or philisophical from building the parthenon. I like to try to simulate financial with the colossus. Although you must have a good amount of coastal cities to get the most out of it, you have a great chance of getting it because as and industrial leader, you get to make the required building for the colossus(forge) at double speed. Speaking of the forge, it is one of the most powerful buildings you can build in the early game, right next to courthouses, and maybe even more powerful than them. The obvious bonus of forges is a production boost of 25%, which is great whether you are a builder or a warmonger or both. However, you should not overlook the other effects. If you can get the required metals (gold, silver, gems) you get an extra happy face for each one! A possible 3 bonus of happiness makes the forge potentially the best building there is in the game. also, the engineer specialist is nice to have for any cities that are low on hammers. All in all, Industrious just seems to offer more of everything, and when playing a strategy game, the more strategic choices one has, the better.
2. Financial:
- 1 extra commerce on any plot that gives 2 or more
-Advantages: Financial is considered by many to be the most powerful trait in the game. I probably would have it number one if you could still build banks at double speed. It is a great bonus to have because commerce is essentially everything. It controls research, it controls how many units you can support and supply, and it controls how large your empire can be. So obviously, the more commerce the better. One who uses financial will almost certainly be building a lot of cottages. Cottages provide a great reward to anyone who is disciplined and committed to growing their economy early. But like all rewards, there is risk involved. Aside from the micro-managing of every tile to get them to balance out just right for maximum cottagation (t.m.) Their is always the worry of being attacked and losing either your city that you've invested so many turns developing, or having your full grown towns pillaged. But to those who overcome, There is a mid to late game complete financial and scientific supremacy awaiting. You don't have to do a pure cottage spam to get the benefit of financial, but thats like having a porsche and never speeding.
3. Organized:
-civics upkeep half price
-double production speed of courthouses
-double production speed of lighthouses
Advantages: Organized is my favorite trait. Many balk at the half price civics and talk about how little gold it saves. One thing they forget to think about is that you do nothing to recieve the bonus, you don't have to found a religion and build a shrine, you don't have to cottage spam and wait a hundred turns, it's there from start to finish, and while some people get in a financial crunch and fore go their favorite civic or most needed civic at the time, the organized player rarely gives it a thought. I find that when I am not organized I can have about 4 or maybe 5 cities before i start to feel the upkeep cost getting heavy. In contrast, I can build about 5 to 7 cities when i am organized before feeling the same effects. While I know that organized does not have any direct effect on city maintenance, It certainly does have an indirect effect of off setting some of the cost by how much you are saving on civics. When you can expand your empire an extra couple of cities in the early game, you know you have a distinct advantage. double production speed of courthouses is an empire builders dream. If you've ever had a sprawling empire with a crumbling economy and had to pay full price for a courthouse, you know what i'm talking about when i talk about how great cheaper courthouses are. And when you can quickly build 7 of them, you qualify to build the mother of all courthouses, the forbidden palace. double production of the lighthouse is just the cherry on top of the sundae. My dad used to always say, "It's not what you make, its what you save." This is so very true if you are organized.
4. Philisophical:
-100% bonus to great people points
-double production speed of universities
Advantages: Philisophical to me is one of the really fun traits in the game. What can be more fun than cranking out various great people each with special super powers that can help to turn the tide of the game in your favor? great people are cool and very strategic. whether you use them to time a golden age just right, dicover a tech, or inbed them in your cities as super specialists, the strategic choices are almost endless. if you employ the civic caste system, you can have greater control over what type of great person you get. Want to impose your culture on your neighbors? make some great artists, want to make a super science city? settle all of your great scientist in your science city along with the acadamey and oxford university. or how about commerce and production? Then consentrate on great prophets and settle them in the city of your choice. Apart from all of the great person fun you can have, you will also be building some super cities that will help put you in the lead for production, science and gold. Double production speed of universities will greatly help you in your science city because when you get 7 universities twice as fast, you can build Oxford univeristy a lot sooner than you would if you had to build them at regular speed.
5. Agressive:
-melee and gunpowder units begin with combat 1 promotion
-double production speed of barracks
-double production speed of drydocks
Advantages: With melee and gunpowder units starting with the combat 1 promotion, the aggressive civ gets a head start on the promotion tree. This makes for interesting strategic choices to be made which can give you the advantage on the battlefield. If you have a barracks, vassalage civic, and Theocracy civic, you can really have fun upgrading some units and specializing them. So, just as great people and specialists can help specialize a city, so can this combo of unit promotions help to specialize your army. For example, say you have an enemy that has a strong army and you want to use a flanking surprise attack. If you have galleys, or better yet galleons, you could take your combat one promoted axemen, swordsmen, or macemen and use their next promotion for combat 2, followed by amphibious and basically create your own mideival navy seals! Agressive also gets to build barracks and drydocks twice as fast which are a great help in producing promoted units, and drydocks enables you to produce naval units much faster with promotions.
6. Creative:
-All cities recieve +2 culture/turn
-double production speed of theaters
-double production speed of coloseums
Advantages: I really like this trait. I wish I could rate it higher. but one of them has to be number 6
. + 2 culture a turn is really nice, especially in the early game. The only thing more fun than watching your borders push outward without having to build anything is watching your borders engulf your neighbor's city that was stupidly placed next to your borders. It is a sweet feeling to take over a city without firing a shot! This bonus is enhanced by some very good culture buildings. The theater is great for extra border pushing, and if you have dyes, will add happiness. Both buildings will increase happiness when the culture slider is in use. This makes for a powerful weapon in times of war. Just by moving your slider you can quench war weariness if you've built your cheap theaters and coloseums. In short, border pushing+extra happiness during wartime= 
for your enemies
still working on this list.... i had to take a break, i will edit and finish later
1. Industrial:
-50% production bonus of wonders
-double production speed of forges
-Advantages: Industrial in my opinion is the strongest single trait in the game. The bonus for constructing wonders offers a great variety of possible strategies. It helps you to tailor make a strategy based on the type of wonders you go for. The wonder bonus also enables you to simulate some of the other traits such as creative from building stonehenge, or philisophical from building the parthenon. I like to try to simulate financial with the colossus. Although you must have a good amount of coastal cities to get the most out of it, you have a great chance of getting it because as and industrial leader, you get to make the required building for the colossus(forge) at double speed. Speaking of the forge, it is one of the most powerful buildings you can build in the early game, right next to courthouses, and maybe even more powerful than them. The obvious bonus of forges is a production boost of 25%, which is great whether you are a builder or a warmonger or both. However, you should not overlook the other effects. If you can get the required metals (gold, silver, gems) you get an extra happy face for each one! A possible 3 bonus of happiness makes the forge potentially the best building there is in the game. also, the engineer specialist is nice to have for any cities that are low on hammers. All in all, Industrious just seems to offer more of everything, and when playing a strategy game, the more strategic choices one has, the better.
2. Financial:
- 1 extra commerce on any plot that gives 2 or more
-Advantages: Financial is considered by many to be the most powerful trait in the game. I probably would have it number one if you could still build banks at double speed. It is a great bonus to have because commerce is essentially everything. It controls research, it controls how many units you can support and supply, and it controls how large your empire can be. So obviously, the more commerce the better. One who uses financial will almost certainly be building a lot of cottages. Cottages provide a great reward to anyone who is disciplined and committed to growing their economy early. But like all rewards, there is risk involved. Aside from the micro-managing of every tile to get them to balance out just right for maximum cottagation (t.m.) Their is always the worry of being attacked and losing either your city that you've invested so many turns developing, or having your full grown towns pillaged. But to those who overcome, There is a mid to late game complete financial and scientific supremacy awaiting. You don't have to do a pure cottage spam to get the benefit of financial, but thats like having a porsche and never speeding.
3. Organized:
-civics upkeep half price
-double production speed of courthouses
-double production speed of lighthouses
Advantages: Organized is my favorite trait. Many balk at the half price civics and talk about how little gold it saves. One thing they forget to think about is that you do nothing to recieve the bonus, you don't have to found a religion and build a shrine, you don't have to cottage spam and wait a hundred turns, it's there from start to finish, and while some people get in a financial crunch and fore go their favorite civic or most needed civic at the time, the organized player rarely gives it a thought. I find that when I am not organized I can have about 4 or maybe 5 cities before i start to feel the upkeep cost getting heavy. In contrast, I can build about 5 to 7 cities when i am organized before feeling the same effects. While I know that organized does not have any direct effect on city maintenance, It certainly does have an indirect effect of off setting some of the cost by how much you are saving on civics. When you can expand your empire an extra couple of cities in the early game, you know you have a distinct advantage. double production speed of courthouses is an empire builders dream. If you've ever had a sprawling empire with a crumbling economy and had to pay full price for a courthouse, you know what i'm talking about when i talk about how great cheaper courthouses are. And when you can quickly build 7 of them, you qualify to build the mother of all courthouses, the forbidden palace. double production of the lighthouse is just the cherry on top of the sundae. My dad used to always say, "It's not what you make, its what you save." This is so very true if you are organized.
4. Philisophical:
-100% bonus to great people points
-double production speed of universities
Advantages: Philisophical to me is one of the really fun traits in the game. What can be more fun than cranking out various great people each with special super powers that can help to turn the tide of the game in your favor? great people are cool and very strategic. whether you use them to time a golden age just right, dicover a tech, or inbed them in your cities as super specialists, the strategic choices are almost endless. if you employ the civic caste system, you can have greater control over what type of great person you get. Want to impose your culture on your neighbors? make some great artists, want to make a super science city? settle all of your great scientist in your science city along with the acadamey and oxford university. or how about commerce and production? Then consentrate on great prophets and settle them in the city of your choice. Apart from all of the great person fun you can have, you will also be building some super cities that will help put you in the lead for production, science and gold. Double production speed of universities will greatly help you in your science city because when you get 7 universities twice as fast, you can build Oxford univeristy a lot sooner than you would if you had to build them at regular speed.
5. Agressive:
-melee and gunpowder units begin with combat 1 promotion
-double production speed of barracks
-double production speed of drydocks
Advantages: With melee and gunpowder units starting with the combat 1 promotion, the aggressive civ gets a head start on the promotion tree. This makes for interesting strategic choices to be made which can give you the advantage on the battlefield. If you have a barracks, vassalage civic, and Theocracy civic, you can really have fun upgrading some units and specializing them. So, just as great people and specialists can help specialize a city, so can this combo of unit promotions help to specialize your army. For example, say you have an enemy that has a strong army and you want to use a flanking surprise attack. If you have galleys, or better yet galleons, you could take your combat one promoted axemen, swordsmen, or macemen and use their next promotion for combat 2, followed by amphibious and basically create your own mideival navy seals! Agressive also gets to build barracks and drydocks twice as fast which are a great help in producing promoted units, and drydocks enables you to produce naval units much faster with promotions.
6. Creative:
-All cities recieve +2 culture/turn
-double production speed of theaters
-double production speed of coloseums
Advantages: I really like this trait. I wish I could rate it higher. but one of them has to be number 6
. + 2 culture a turn is really nice, especially in the early game. The only thing more fun than watching your borders push outward without having to build anything is watching your borders engulf your neighbor's city that was stupidly placed next to your borders. It is a sweet feeling to take over a city without firing a shot! This bonus is enhanced by some very good culture buildings. The theater is great for extra border pushing, and if you have dyes, will add happiness. Both buildings will increase happiness when the culture slider is in use. This makes for a powerful weapon in times of war. Just by moving your slider you can quench war weariness if you've built your cheap theaters and coloseums. In short, border pushing+extra happiness during wartime= for your enemiesstill working on this list.... i had to take a break, i will edit and finish later
I wasn't trying to insinuate that one "leader" would be so much better than the other by rating the traits as i have. trait combos is something that i have thus far failed to address in my rating. As you mentioned, there are very many factors that vary from game to game as situations dictate. I may think that expansive is the weakest overall trait in the game, but I certainly don't think it is totally useless. When comined with a good complimentary trait such as spiritual it has a way of getting a boost and increasing its overall strength. I also didn't want to imply that financial and industrious are necessarily the greatest combo of traits in the game. Industrious and philisophical could be interesting... 
Thanx for pointing this out because you are exactly right, i just didn't think about it yet. My purpose for rating traits is not to bolster one and put down another, but rather to open peoples eyes to some under rated traits and have a better appreciation for them. In fact, I refuse to dog any of them because in the right situation, you need the right trait, not someone elses (like me) opinion of which is best.
. The problem was that one of the testers was able to get like a third of the tech tree from great people. I would not expect this combo in warlords.
