I would say the A.I. is best in NHL 2K3 by far, it is actually fantastic as I discovered only recently. The only problem are the goalies are brick walls in this game
Then it all started to fall apart slowly, where 2K8 has the worse a.i. in all 2k history. Which was really shame become the goalies in this game were really good.
I think if 2K8 has 2K3 a.i. and less bugs, we would still have hockey game from 2K today.
2K10 is the game that is closest to the 2k3. It even have a lot of animations from that great old game.
The tragedy of 2k9/ 2K10 is that somebody in lead of these latest games believed that people will love if they make the player models cartoony, ice blue, gameplay full of breakaways and many of the animations 2-3x faster than in real life.