I haven't personally sampled it, but Guitar Hero III seems an awesome prospect as far as gaming on a Mac goes. Unreal Tournament too, I'd agree with that. xD I see from your post that you already play WoW, so there goes my primary Mac game.
I'm lucky when it comes to gaming, my fiancée has a Wii, PS2 and an xbox 360, and we both play WoW together, so it's all good.
