Which game for xbox 360?

Hi just a quick question, I recently loved mass effect 2 completed it etc traded it in for bioshock 2 which to be honest i dont like at all i loved the first one but this just seems well boring to me. I was wondering what games people can recomend to me.

I currently own fifa 10, Left 4 dead 2, GTA, Bioshock 2.

Or shall i hold off until aliens vs predator 2?

Thanx for the help

The Call of Duty games are good. Also, you might want to save your money for the games that are coming out like Final Fantasy XIII (March 9) and Splinter Cell: Conviction (April 13).