I liked 2k9 over NHL09, but with the new season I chose EA 10.
Why?
Well not only are the graphics and AI better, but something EA did sealed the deal for me. I have a PS3, and prior to NHL10, you weren't allowed to add your own music to the game. Now with NHL 10, Im able to add in the NYR intro, Authentic NYR goal song. (The whoaaaaaaa Song) and also add in the NYR Victory song after a NYR win. Im such a stickler for detail that something little like this would make the decision for me.