Only listing Xbox 360 exclusives:
1. Shadow Complex
2. Tales of Vesperia
3. Crackdown
Shadow Complex is one of the best Metroidvania games I've ever played, the biggest flaw was the ending. Tales of Vesperia is a great Tales game (yes I know it's coming out on PS3 in Japan but as far as I know the PS3 version hasn't been announced for the US yet).. Crackdown is easily the best GTA style game I've ever played.