I've got an extra code for System Shock 2
 

It was from the gog.com promo, and I already have the game. It's a GOG code that expires 15th December. If anyone is interested please let me know.
(Just to clarify, the code has to be redeemed before 15th December, but once you do it the game is yours forever. GOG doesn't use any DRM in fact).

Link to the game:
http://www.gog.com/game/system_shock_2