Co-Op:

Rainbow Six Siege
Rocket League
Bro Force
Insurgency
Space Marine
God Mode
Spin Tires
Vermintide & Vermintide 2
Space Hulk: Deathwing
Skyrim (soooooooon)
Red Dead Redemption
PayDay2
Doom3:BFG Edition
theHunter
Arma (all games)
ShellShock Live (also Vs)
Serious Sam BFE (also Vs)
Left4Dead2
Shark Attack Deathmatch 2

Versus:

Ticket to Ride
Colt Express
Carcassonne
Talisman
Sonic Allstars
Tabletop Simulator
Depth
Road Redemption
For Honor
Mysterium
Doom
Just Cause games