well, people have already mentioned the majority of the good games out right now.

Thought I'd add Klonoa 2 to the list. IT's got a bit of a kiddy look to it, but it's an awesome 2 1/2-d platformer and the gameplay isn't kiddy stuff.

Also, if you can find it, try the first Klonoa for the PS1. It's the same idea as the first one. The ending is absolutely heart-wrenching. But the game is awesome.