I'm a newcomer to the Galactic Civ games, I just heard of them about a week ago. Bought and downloaded the game last night, and I have to say that so far it utterly exceeds my expectations. Seriously. This is what MOO3 _SHOULD_ have been like, rather than the disappointment that it ended up being. Sure, there are little things here and there that I would change, but they are all very minor and the game as a whole is wonderful. I've gotten my butt kicked twice, thinking of turning it down to an "easy" setting until I get the hang of things.
Oh, and one of the things that I really like is the humor, as well. For example, the highest level Population Growth bonus being listed as "Don't Ask." The Monty Python references and other comedic material in the research completed screens, and so on. Just enough to make it fun without getting too corny.