Halo Reach - Fall 2010 (360)
I dare say no game series has had a greater impact on co-op gaming in the past 10 years than Bungie's Halo. Co-Op play has been a staple of the series since the beginning, and with each successive game the co-op modes have gotten deeper and more open. With what we've seen from the teaser trailer of Reach, we're hoping that holds true once again. Could we see 6 player co-op? True squad based gameplay? Only time will tell, and it will tell all this fall.
Rage - Fall 2010 (360/PS3/PC)
Co-Op: 2 player co-op specific missions
id may have fathered the co-op first person shooter, but it's been some time since they revolutionized things. Don't expect it to change much for Rage's co-op mode, as players won't even be able to play through the main game's story together. We've seen hints that the co-op stuff may be very tightly designed for two players, so perhaps that'll hold true in this post apocalyptic shooter.
Brink - Fall 2010 (360/PS3/PC)
Co-Op: 8 player online co-op
Brink just up and came out of now where, becoming an obscurity to a must have co-op title. 8 players with unique roles, dynamically changing missions, beautiful graphics and drop-in and drop-out play already make Brink a strong contender for co-op game of the year. The character progression and experience system are going to keep people coming back for more, making this the Borderlands of the Fall of 2010.