Co-Op Help!

I'm looking for another amazing co-op game, one that will keep me occupied for a while with a friend of mine.. and I can only find army of 2 40th day... >.> not much for variety. I just wanted to know what anyone else might suggest?

Borderlands

Fable II

Gears of War

C&C red alert

Left 4 Dead

Halo Wars

Halo3

Cod5

Played any Borderlands? That's a great one. Also Left 4 Dead 2!

Left 4 Dead 1 and 2

Gears of War 2

Borderlands

Modern Warfare 2 Spec Ops

Halo 3

Left 4 Dead 1 and 2

Gears of War 2

Borderlands

Modern Warfare 2 Spec Ops

Halo 3

Raiden004

If you and your friend are really into shooters, I'd agree with everything Raiden004 said. You may also want to skim the Wikipedia list of Xbox 360 Co-op Games and see if you find anything of interest. Seems a little limited, though..

EDIT:Another link for suggestions. Plus, I forgot to add my personal recommendation, which is Gears of War 2.

Along with the above posts, there is also Resident Evil 5 and Too Human. :D