Bored with what youve payed for? Want something different? Cheap?
Try one of these. At one point or another i have tried all of these. There are many more out there but these are the ones i can "vouch" for.
Soldat
: Fast paced side scroll shooter. Its very good!
America's Army
: High quality FPS developed by the Army. I believe this is downloadable via Steam too.
Assault Cube
: This is a doomish style FPS decent quality and because of its engine can run on most any common OS ( win mac *nix)
F.E.A.R Assault
: Its F.E.A.R but F.R.E.E.
Open Arena
: A Quake like game.
Quake Live
: Quake but free.
Wolfenstein: Enemy Territory
Edit:
MMO
Anarchy Online
Dungeons & Dragons Online
: i played this one, its alot like Might and Magic.
Pirates of the Caribbean online
: I messed with this but lost interest.
Rappelz
: I have heard this is fun but have not tried it myself. Gpotato also offers some other free games.. They're Micropay games but the core is free.