Found something else...
Cool - Here's the skinny from that list.FPS
All games are already posted except for Far Cry and Tom Clancy's Ghost Recon - Those games were free for a time period but are no longer free. If you install them and did not have from the time period they were available they will not play. There is a crack online that can undo this for you but that makes the game illegal.
On September 1, 2007, Ubisoft released a single player-only version of the game as ad-supported freeware on FilePlanet. According to Ubisoft, the offer is no longer available.
All games are already posted except for Curator Defense and Dofus Arena. Dofus Arena has not be available to play for some time now, their site says coming soon. CD has a serious lag issue the last time I tried to play it. According to their site it's been fixed but I have yet to give it a spin. I will check it out soon.RPG
All games are already posted (and fall into MMORPG not RPG genre) except for Space Cowboy, There.com and Space RPG. Space Cowboy and There.com are dead. Space RPG (the last time I played it) came with pop-ups. In other words, you would install it and a pop-up would come up, you finish playing it a pop-up would come up...you want to uninstall it....a pop-up would come up. I don't post games that do that even if they are free and legal. If anyone knows otherwise, let me know and I will check it out.MMORPG
All games are already posted except for Furcadia, Dofus and Voyage Century Online.Action/Adventure
All games are already posted except for Prince of Persia: Sands of Time, Rayman Raving Rabbids and The Room War. The first two are illegal at this time for the same reasons the games in the FPS section I covered above were.
The Room War is a free game from the Alien Ware competition. Others can try this one out if they like it's a really short game to show off the product and looks nice but not post worthy for me.Racing
All games are already posted.Space Sim
That game link is dead. There is a new project up but it's in early alpha stage...lots of bugs but for the adventurous you can try it out here - http://scp.indiegames.us/Sims
All games are already posted except for Blockland, Ore no Ryomi 2 and Space Merchats: Conquerors.HL2 Mods
The final section requires a purchase which is blasphemy.
ALL games posted by users from the OP down to the last have been posted except for the ones that required a purchase.
BTW if you want to see some other freeware games that I don't post up check out Pixel Prospector's site - It's in the resource section of the OP of this thread. He has links to other sites and other threads on the web like this one. I can't guarantee that they are all free and legal as some people just posted anything including recently pirated games.