M rated games for a 12 year old?

I'm 12 years old and have a 360 and a ds and a wii. I want to play rainbow six Vegas, gears of war, call of duty 4, crackdown, Army of Two, and Unreal Tournament 3 when it comes out for the 360. I'm a straight A student and I play football and lacrosse. I own and play Halo 3, ins Creed, all the call of duty games except 4, mercenaries and more teen rated games. I don't want GTA, that sounds fun but is not appropriate for my age. Please help me convince my parents at least one of these games isn't too bad for ME.