Can't vote for one but I see that is not the point here. I continue to have fun playing in leadership roles all the while playing a co-op Civ game. Lately, I've been finding it better to focus on a few goals rather than too much - which can be quite exhausting, as I'm sure some can relate.
The greatest times are the chat for me. When it can move along, it is like listening to my favourite sports team on the radio: generating leaders, completing wonders, wartime moves... all lots of fun.
While I've recently realized that the game is different to everyone, I'm glad Eyrei has posted in here to point that out. Just because some may participate for the game itself, some will prefer talking Constitution and politics all the time and some will be spectators, and yet others will debate strategies, and so on. For whatever anyone gets out of it, that is good; the quality of the game is in the participation of the citizens.