For ATI/AMD (Radeon) graphic card users: Link: steam://hardwarepromo/305 - Half-Life 2: Lost Coast - Half-Life 2: Deathmatch For Nvidia (GeForce) graphic card users: Link: steam://hardwarepromo/609 - Portal: First Slice (demo) - Half-Life 2: Lost Coast - Half-Life 2: Deathmatch For all Steam users: Between [1][4]: steam://install/29140 Codename Gordon: steam://install/92 COIL [1]: steam://install/31500 Mightier [1]: steam://install/29150 Peegle Extreme: steam://install/3483 Sam & Max: Episode 4: steam://install/8230 TrackMania Nations Forever [2]: steam://install/11020 Free addons and resources for already purchased games: Counter-Strike (Counter-Strike Steamworks Beta access [3]): steam://install/150 Half-Life (high definition models - comparison): steam://installaddon/halflifehd (uninstall) RACE 07 (Crowne Plaza Raceway track) [5]: steam://install/8670 Official MODs: Age of Chivalry (requires Source SDK): steam://install/17510 D.I.P.R.I.P. Warm Up (requires Source SDK): steam://install/17530 Dystopia (requires Source SDK): steam://install/17580 Eternal Silence (requires Source SDK): steam://install/17550 INSURGENCY (requires Source SDK): steam://install/17700 Mare Nostrum (requires Red Orchestra): steam://install/1230 Synergy (requires Half-Life 2): steam://install/17520 Zombie Panic! Source (requires Source SDK): steam://install/17500 Steam demos: http://store.steampowered.com/search...=&category1=10 Mods: http://store.steampowered.com/search...&category1=997 [1] mistakenly listed as a demo on storefront [2] already included on TrackMania United [3] deployed and deprected, but continues working [4] mistakenly named as a demo on "My games" list [5] will install addon on your title and a demo to run feature standalone [ source : "http://forums.steampowered.com/forums/showthread.php?t=851573"]Free Steam games list - Steam Users' Forums ] Cool @ Steam URLs. I didn't know that was even possible till I saw researched this and found this thread.