I'm going to get an Xbox 360 for christmas, unless another console comes out, what games should I get?

I already have in's Creed, Halo 3, Call of Duty 4, Turok, and Killzone Liberation on my list. Wait is Killzone even on the 360. And don't laugh because I'm getting it late. My little 9 year old brother still sees it as new and I'm basically getting it for him.