Counter-Strike
Counter-Strike: Condition Zero
Counter-Strike: Global Offensive
Counter-Strike: Source
Day of Defeat
Day of Defeat: Source
Deathmatch Classic
Half-Life
Half-Life: Blue Shift
Half-Life: Opposing Force
Half-Life Deathmatch: Source
Half-Life: Source
Half-Life 2
Half-Life 2: Deathmatch
Half-Life 2: Episode One
Half-Life 2: Episode Two
Half-Life 2: Lost Coast
Left 4 Dead
Left 4 Dead 2
Portal
Portal 2
Ricochet
Team Fortress Classic
Team Fortress 2 (free-to-play)