Play against Chess AI....

Smart enough to run for their lives, sometimes anyway.
Smart enough to pick up weapons from the floor/available on the stage, heal themselves, attack NPCs around you.
Some thugs should be "unique" in a game, not as if they were mass-produced, you could hurt them but they could call for backup or retreat and ambush you later.

yeah they can't get much better or they would destroy you eventually. Any game where you mow down hordes of enemies would be impossible unless the player is supposed to be overpowered (like in God of War).
Imagine a Call of Duty campaign where every enemy force is played by a human. You'd never make it to the end of any level. The AI needs to have a certain degree of stupidity.

As Scoobes said, Far Cry is an excellent example of great AI that is at the same time hardly believable. Completed Sniper Ghost Warrior yesterday and it was the same there. They can see you from miles away, through the vegetation and they don't need snipers to shoot you down from any range. Also if they are alerted once they automatically turn in your direction within seconds.

I think most problems we encounter with the AI are the bugs. The NPCs aren't dynamic enough to correct their own errors when they make some and that makes them look dumb.

I only demand if you give me an escort mission that the AI has the good sense not to be suicidal or constantly stuck on tricky things like "stairs" or "turning around a corner".

Not alot of games have that perfect balance for AI.

Chess AI is brutal

Better than this.. :o

i think we will see that fixed in the last of us

This is genious. Hasn't anything to do with the AI though.
The developers just didn't think that anyone would such things.

I want the creative type of AI from the Halo series to be standard and for the AI in future Halo games to continue to evolve and get even more fun to combat.