Halo's 1, 2, and 3 (if you dont have any of these games, or ever have, get out.)
Armored Core 4 (scrumtrelescent graphics, but way too short of gameplay, and not enough customization.)
Viva Pinata (because my mom said that if i didn't have an "E" game for my sis, she'd toss the 360)
Gears of War (nah, stick 'em with a smoke grenade)
Guitar Hero 2 (I suck so bad at that game-- *cry* I own at Air Guitar, tho. XD)
Assassin's Creed (totally setting it up for Creed 2 -- the guards are rediculously stupid, tho. I stabbed a guy in front of another guard, sat down, and went completely unnoticed)
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Can't wait for:
is there a Mech Assault 3 in the works, anyone? Awesome Xbox game (1 and 2, i mean).
Halo Wars (again, if you don't want this game, get out.)
Fable 2 (you have a really smart (AI-wise) dog: what other reason do you need?)
oh yeah, and you may have heard of this little number, may have flown under the radar though...
Starcraft 2!!!!!!!!!!!!!!!!!!!! ((main page, watch the cinematic trailer!! if the unit and building bio's aren't working, go to the "Features" page))
http://www.starcraft2.com/