Greetings.
Felt this was an appropriate place to enter the forum dialogue.
My opinion is that Civ 5 is a great strategy game.
After the G&K expansion, gameplay improved considerably.
Things that I like about the game....
1. Military.
1upt is a brilliant addition to the civ franchise.
The combination of Ranged units, mounted units, melee units, and customisable promotion paths allow you to have a wide variety of strategies both against human and AI players.
The different types of military units combined with the terrain of your combat zones also influence the strategic placement of military units for both attack and defence.
The introduction of 100 HP in the G&K expansion also improved the gameplay.
2. City management.
The maintenance costs of buildings forces you to make strategic advances in your building choice, particularly on higher difficulty levels. Combined with a very limited production time, this makes it very difficult until the really late game to spam buildings.
Instead, I have found that long term city planning strategies such as designating one city to build military units (place near Iron, place manufacturies around it, build buildings to give military promotions,) coupled with one science based city, (jungle tiles, academies, on river for population growth rather than production priority), and a financial centre (treasury, luxury resources, trading posts) is a good way to go.
3. Tech tree and inflation.
The balance of the tech tree is near perfect, with the increase in science to fund new technologies as well as the increase in production to build new units advancing at a rate such that runaway tech leaders do not often happen. (Although one time France AI won a space victory in 1831, but that was an exception to the rule.)
The tech tree also offers long term research plans that allow certain areas of tech to be left for long periods of time while developing huge advancements in other areas. This allows for different approaches to both domination attack strategy (land units, naval units, mounted units) and non-aggressive strategy (economic prowess, or technological prowess?)
4. Social policies.
The social policy tree system also allows for a lot of variability in play style. Foor example, A non-aggressive civ trying for a cultural victory surrounded by aggressors may just be saved by completing the universal suffrage policy, allowing them to field a larger army for defensive purposes. Combining this with oligarchy from the tradition tree allows for a non-agressive no maintenance military force.
5. Diplomacy
The unpredictability of the AI and their willingness to betray you to further their own agenda makes for a far more humanlike experience in the single player game.
The AI military strategy may need some improvement, since they don't really understand strategic placement or terrain benefits, but a large attack force combined with a sudden reversal of friendship can leave your empire ravaged before you have time to respond.
The AI can be reasoned with and bought off, and also played off against each other, under the right circumstances. The fact that they remember your agressive advances against other civs also serves as a limiting factor in the expansion of your empire.
6. City states.
The introduction of city states opens up a new and interesting dynamic and allows for several strategic maneuvres against your opponents, such as donating military units to them to fight your enemies, resulting in a proxy war that can weaken a stronger empire as they lose troops but don't come near your empire.
7. Late game
I like the way that the technology advancement obsoletes certain city attack strategies, forcing you to rethink your attack plan mid game.
Here's a good example from a recent game I played as the Dutch. Having conquered North America in the medieval era, I started a long term naval plan to conquer the Romans in Asia. I brought in 3 Galleass from the Renaissance era, got them up to +1 Range and Logistics promotion, then upgraded to Frigates. Along with that, I build yourself 2 or 3 Sea Beggers (Dutch UU.)
It's time for naval domination. I send my ships across continent and start taking down Roman coastal cities one after another. And then.... the enemy discovers flight, places 3 bombers in a city which outrange your ships by 4 tiles, and bang, my navy is gone in 2 turns.
8. Modding community and Mods.
There are so many amazing mods made by dedicated enthusiasts that improve the game in so many ways that there's no time to list them all here. Suffice it to say the mods have been listed here on the forum and talked about already.
Things that aren't so good.
1. Turn times.
This game is carnage on the hardware, particularly on large and huge maps. Late game huge earth can take a full half hour to load if there are a few civs with airforces and naval fleets.
2. DLC.
DLC makes multiplay difficult. The cost for all the DLC is very high if you want to get everything. Currently I only have Vanilla + G&K, would love to try some more DLC but for the sake of playing a couple of scenarios or an extra Civ with no real game features, I say, stick with the modding community.
3. Multiplayer.
Lag, disconnectivity issues, inability to save games, poor servers and unfriendly server interface, to name a few things that are wrong with the multiplayer.
4. Lack of excersise and shirking of responsibility of adulthood.
The goodness of this game means that things I should have done months ago remain unfinished.
Very long first post, and thanks civfanatics for being a good forum.