If you want something that will challenge you, and is fun to play, you could do far worse than Crucial's re-release of Master of Orion II. Man that game can be evil. The research tree alone makes you want to obtain a doctorate in advanced theoretical quantum mechanics!
Curiously enough, like Civ its not graphically beautiful, but it is one of those games that you can play and play. Also, it seems that those boys are at it again, and MoO III should be out in the last quarter (us fans have only had to wait about five years for it). If you want to check it out then
http://moo3.quicksilver.com/
should do it. The ground combat alone would suggest that this game will be the equivalent of the Dark Lord himself coming for dinner on Sunday. Which is nice.
BTW Hello Father Bronze. I was invited over by Epona to spread the faith of the "Alloy Allies". Well done Epona. Sweet.
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Making running away an art form