Oh this is definitely a good thread. Sometimes the AI coding is just a dick. I'll put forward a couple of examples.
I know this isn't really AI but game mechanics but it needs to be includedResident Evil 4 - Ashley
"Oh, I'm sorry, you cant jump down that two foot ledge by yourself without someone to catch you?"
"Oh, I'm sorry, you run into the enemy because of what reason?"
Just generally everything but that was my own main problems with her for the most part, was that if you left her free to move around in a fight, she'd just stand there while someone took her. Resident Evil 5
also had shit, shit co-op AI. Going through the tunnel that has all the lickers in it, I end up just taking guns off my partner completely now because others wise they generally just fire, even if I have them on cover, so they shouldn't fire unlessthey are being attacked, stupid fricken AI.
But hey, I won't doubt that if you take away the hangun, they can be mighty useful in a fight on hard with a good weapon.
Some of the glitches in Crysis 2
also got on my nerves. Sometimes you'd be standing right in front of an enemy and they would just refuse to shoot you and instead run away to take cover or get distance. This the humans of course, the aliens were mostly fine. And hey, concidering I suck at aiming, it made my life a bit easier, but STILL.
And Fallout New Vegas
Need I say more.
On the Assassins Creed AI though, they definitely got a lot smarter in Ac2, but in AC3 its incredible. The people are not only smart and interest realisticly, as well as personally to you, but the animal Ai is awesome. if a dog sees a cat in the street for example, it will run towards it and the cat will run off. :) Its rare to see but it was brillant when I did.
The only thing I miss is the spontaneous comments from people that you got in AC1, like when you're climbing and they would call you crazy and wonder what was wrong with you.