What are good games with good co-op

Thier was just a thread like this that got closed. I suggest using the game recomendation thread and be more specific about "co-op". You talking local campign/MP or XBL campaign/MP?

Halo 3, Halo 3 ODST, Gears of War, Gears of War 2, Left 4 Dead, Left 4 Dead 2, GRAW games I beleive. I will post more as I remember.

Army of Two and sequel.

Borderlands.

Call of Duty: World at War.

Dynasty Warriors games.

Marvel UA 1&2

Rainbow 6 Vegas games.

Those are some good ones that I have enjoyed. Their is also all the Guitar Hero/Rock Band games but those aren't your traditional games.