You know, I have owned Civilization IV for a while now. At first I was lost, and didn't know what to do, and still have things to learn, but it is incredibly fun. Somehow I managed to become the number one nation, but those damn French are an annoying bunch, requesting tributes and crap.
I feel I'm barely scratching the surface, and still haven't downloaded Beyond The Sword. If Civilization V is as good as this, I'm sold.
Edit: Best GTA by far. I'd get it, but it is not available in my region.... Do mods work with the Steam version?