Which XBOX-XBOX360 titles should I buy?

[1337 Gamer]

Xbox: Crimson Skies, Knights of the Old Republic 1 & 2, Jade Empiere, Halo, Halo 2
Xbox 360: Halo 3/ODST, Mass Effect 1 & 2, Gears of War 1 & 2, Left 4 Dead 1 & 2, Halo Wars, Forza 3, Lost Oddessey.

I only posted Exclusive games as you already have a PC and a PS3.