Call of duty Black ops doesn't have any coop other than the zombies/Online if you count being on a team together.
Second Like Dekasav said Call of Duty 5 has a 2 player Story mode, Plus zombies.
Splinter Cell Conviction has COOP
Borderlands Has 4 player coop (its an FPS/RPG Hybrid)
ArmA2 has Coop Big Coop to, but the game is very realistic
Call of Duty Modern Warfare 2 has Spec ops, which are a bunch of 2 player (i think 2 player could be 4) missions that are ranked and such
Deadrising 2 has amazing COOP ( its just fun killing zombies together)
And the list goes on and on, here go on this website and its full of COOP gameshttp://www.co-optimus.com/system.php?id=4&page=0