I thought I'd share some freeware games that I found with everyone.

Barkley Shut Up and Jam!: Gaiden <Rpg> (Just a heads up, but if you are offended by Diabetes and Glaucoma and possibly Aspergers being status effects and possible joking about said conditions you might want to skip this one. I haven't yet gotten that far in the game, but so far I haven't seen anything offensive.)
Trilby: The Art of Theft <Platformer/Adventure>
Seiklus <Platformer/Adventure>
Within A Deep Forest <Platformer/Adventure>
Base Invaders <Strategy>
Cave Story [Crossplatform: Win/Mac] <Platformer/Adventure>
Cube / Cube 2: Sauerbraten [Crossplatform: Win/Mac/Linux] <Fps>
Death Worm <Action>
Dwarf Fortress <Strategy>
UFO:AI [Crossplatform: Win/Mac/Linux] <Strategy>
Bontago <Strategy>
Tremulous [Crossplatform: Win/Linux] <Strategy/Fps>
Narbacular Drop <First Person Puzzle> (The team was hired by valve and later went on to make Portal)
Battle for Wesnoth [Crossplatform: Win/Mac/Linux] <Turn-based Strategy>

If I wasn't so bad at describing things, I'd give you descriptions of them all. Any posts of other free games would be appreciated.

Note: If you try Narbacular Drop, you can get some really weird stuff going on with the portals, I've actually given myself headaches.

http://www.hrwiki.org/index.php/Floppy_Disk_Container