Best Civ Features

Hello I'd like to know what everyone's favorite and least favorite features are from all the Civ games that they've played, along with some things you think could have been improved
Example
Civ V
Favorite feature was social policies, and the graphics (not really a feature...)
Leasr favorite was the warmonger feature because it seems like if you just capture one city everyone automatically hates you.
I think Civ Vs city states could be improved to be more like mini civs and less like random quest NPCs. Also the AI (always the AI!)

his thread may be in the wrong topic, but this is the best topic I saw to put it in. If this should be in a different topic I will happily move it

Civ 5
Best
- New culture victory; wins hands down; Great Works, archaeology, tourism and interesting Wonders...
- Religion; the system is great - religious pressure, conversions, choosing beliefs.... religious wonders
- Animations for wonders; many players don't care much about the visuals but it does add to immersion
- Trade routes, another interesting innovation that incorporates many other features of the game e.g. spreading religion, CS quests, enhancing diplomatic relations, culture victory etc... That to me is the strength of Civ 5 that so many features work along-side & synergize with each other.

Worst
- warmonger hate was overdone but with the new patch I think the balance is about right. so that is cleared up
- AI still struggles; it has improved but choke-points and mountains for example really screw with AI. It's disappointing that the higher difficulties don't have a smarter AI but just give them a cheating head start which means they accelerate too quickly through the early era's (so at Diety you don't really get to experience the ancient & classical era's as the AI get to medieval by turn 80) and you also miss out on most of the early wonders.
- tile improvements; very 1 dimensional and is rather boring implementation - there is no real choice or strategy in improving tiles just connect luxuries, then improve strategic/bonus resources and lastly normal terrain....
Ideally there should be some decisions to make about what to invest workers in. An example could be using workers just to improve tiles or to expend the worker to produce a special tile (sortof like the workboat)
For instance you could consume workers to build towns (which then grow like the cottages/trading posts in Civ 4) as an alternative option to just improving a tile. That way towns can provide a better benefit but cost a worker to build so there is a bit of a trade-off going on..

I would like to see Great Merchants being able to build a plantation and grow new luxuries. That would be a nice strategy for a mercantile civ.