Any good co-op games?

Kane and Lynch 2 (don't know about the first)
Tried it yesterday with a friend, I loved it.

Inversion. Great game. I played alone on ps 3 but it is full campaign co-op. There is the lord of the rings war in the north if you like rpg.

Resident evil 5
Castle crashers
L4d2
orcs must die

Magicka definitely

And Team Fortress 2. It was awesome back in the days, but I don't know about current situation (after it become F2P and the hats stuff)

Left 4 Dead 2.
Portal 2
CS
MoHAA
Quake 3 TA
Unreal Tour
FIFA
Pro
NBA

Red Faction: Armageddon

Lara Croft and Guardian of Light.

Sanctum

Payday the heist is good.
Very good game.

Half life: Sven coop

Payday: The Heist

Borderlands / Borderlands 2

Killing Floor

also the Shogun 2 coop campain is kinda fun

Serious sam, Titan Quest : I.T. is very good in co-op, i loved it.

Besides all that wave based survival games:

If you are into Lord of the Rings I can recommend War in the North. Not the best Game, but if you are a LOTR Fan then it is very enjoyable.

Also, Krater.

If you are into Tower Defense, Orcs must die 2.

If you are into roleplaying, The First Templar.

If you are into platforming, I can recommend "A Valley without Wind". It is a nice game and if you buy it now, you'll get the 2nd part for free in January.

Portal 2, Left4Dead 2, Sanctum, Magicka, Trine 2, and Alien Swarm (but it's much better with 3 or 4 people).
Also; Starcraft 2 and Diablo 3, but haters gonna hate on those.

Serious Sam? ^^

payday, portal 2, l4d2,