@vfb
Scripted, timed scenarios are never a measurement for AI, but only for the players' ability to fight against the running clock
@sevenwarlocks
"AI's that react on a turn by turn basis will never be effective." - that's exactly what the Dominions AI (mostly) does .. go figure.
@DakaSha
I don't know which "modded" Civ4 AI you have played, but I'm pretty sure the "Better AI" mod in it's later versions gives a pretty good AI - and the cheating does not come from the AI routines, but from the difficulty settings, which basically do not do anything else than giving the AI lots of adavantages, but not making it smarter. I always feel that the highest difficulties do not make for harder game, but a worse one, because the whole thing becomes seriously unbalanced, and I have the slight suspicion that they're even
detrimental to the AI because of the missing balance.
Pretty nice AI I also found in the TAM and Rhye's mod, and in AoDII for Colonization.
Actually, Civ4 is the game I play the most at the moment, not because I like it that much - I actually, I rather hate the 3D crap - but because it's the one with the most stable network code and the best AI mods, and it Alt-TABs very fine on my machine...
I own GalCiv2, too, and IMHO the AI is greatly overhyped - and it's a rather simple game, compared to SE4/5, Civ4, Dom3 or others ...
Finally, on the question for a strategy game with a really good AI:
There ain't !!
edit: PS - I should do Kwok some justice. He's doing fine work with this Balance Mod for SE5, and the AI really has become much better. Sadly, with all that additional AI scripting (partly to get around design errors in the hardcoded part of the game) turn generation times skyrockets ... I'm running 15min- end turns calculations now, and I'm barely midgame 