Warlock 2 + Renaissance Mod: Fine Fantasy 4X

I thought the AI was quite good. I payed attention to it closely. I was not happy with the AI in Fallen Enchantress, for example, and it turned me off from that game. With this mod the AI was aggressive, would declare war opportunistically, use a good mix of troops, and try to hold important objectives.

It was the best AI of all of the fantasy 4X games I played.