Caesar 4 is a nice city building game.
Victoria is an interesting empire building game (and should be in the bargain bin for a few dollars).
If you like Civ you could go back to a very old game, Master of Orion 2.
Imperialism 2 is another old game that is excellent (and cheap)
Patrician 3 is an interesting trading game with a touch city and nation building. (and cheap)