my favorites game for the xbox360 has to be Army of 2 and Left 4 Dead. i say army of 2 becuz u need to work together to pass the level and most people think they can do it all on there own. so i think thats a good change. the reason i like left 4 dead is becuz again like army of 2 u need to stick together to survive, if u get pouned by a hunter or grabed by a smoker, you need someone to help you.
Rainbow Six: Vegas 2 Because of it's character customization, unlockable weapons, a rank system you can climb up regardless if you're playing offline/online, and the handy controls. Not to mention how much of a laugh I get whenever a terrorist so much as speaks in it.
halo wars is good game but Halo 3 is definately my favourite game. Basically because i can beat anyone i verse and because of its great graphics and huge multiplayer aspect to it.
cod 4 because it has insaly addictive online play, left 4 dead because it is a really fun game though a bit on the short side, halo wars because its a strategy but its more fast paced but it still requires you to think, halo 3 because it has pretty good online and forge is always fun and finally gears of warb 2 because you have to use cover and cant go in all guns blazing
Mine would be Resident Evil 5 because, it is so addicting and the fact it is easy to get new weapons and you can get unlimited ammo for a gun pretty easily too.