Beautiful Mac Games?

I just ordered the 27" iMac w/ upgraded graphics. I'll admit that I'm not much of a gamer but, then again, I've been using a 13" MacBook Pro for a while. So, not that much encouragement to try. But now that I've got something that can do something, I'd like to see what it can do—as it were.

So, what recommendations do you have for beautiful games that can really make the 27" display shine? I like the looks of LIMBO for dark minimalism and Bastion for great art. Trine 2 also looks amazing. Any more?