Littlebigplanet 2, Portal 2, Socom 4 and Dyanasty Warriors 7 have the best co-op right now this year. Soon Will be Uncharted 3, Twisted Metal, Ratchet & clank: A4O, Deadisland, and Saints row the third. :)

Probably Gears 3. 4 player co-op campaign online(2 player split-screen), 5 player co-op Horde Mode online (2 player split-screen), Beast Mode 5 player co-op online (2 player split-screen). Can't really beat that. As for games that are out right now I would go with either Portal 2 or LBP2.

You should add the Halo: CE Anniversary and Saints Row The third.

For me and my brother it's a tie between Killzone 3 and Dynasty Warriors Gundam 3, with LittleBigPlanet 2 coming second.

Did you guys forget Dark Souls!!?

YOU WANNA LIVE FOREVER?

Resistance 3 is the most important one.

I thoroughly enjoyed playing through F.E.A.R.3 on co-op