Well title states it all. Here is a list of the games:
Call of Duty:Modern Warfare 2
Call of Duty:Modern Warfare 2-Multiplayer
Counter-Strike
Counter-Strike:Condition Zero
Counter-Strike:Condition Zero Deleted Scenes
Counter-Strike:Source
Counter-Strike:Source Beta
Day of Defeat
Day of Defeat: Source
Deathmatch Classic
Dogfighter
Frontlines: Fuel of War
Grand Theft Auto lV
Grand Theft Auto: Episodes from Liberty City
Half-Life
Half-Life 2
Half-Life 2: Deathmatch
Half-Life 2: Episode One
Half-Life 2: Episode Two
Half-Life 2: Lost Coast
Half-Life: Blue Shift
Half-Life: Opposing Force
Left 4 Dead
Left 4 Dead 2
Medal of Honor(TM) Multiplayer
Medal of Honor(TM) Single player
Portal
Ricochet
Team Fortress 2
Team Fortress 2 Beta
Team Fortress Classic
You can offer via moneybookers only (maybe paysafe card but you pay higher), or zszc silkroad online water items/gold/avatars/ sos items/ +9/7 items