Morenatsu.
Liturgist
To be honest, I don't really care what the AI in a game is as long as it meets the average standard for functionality. Anything past that needs to contribute something interesting to the gameplay, or else it's just showing off. What matters most is encounter design. FEAR's was fine, but not anything especially memorable, really. It's just that it was the last major FPS actually made for PCs that was any good.