http://slickdeals.net/permadeal/34302/prince-of-persia-sands-of-time-pc
Prince of Persia and the Sands of Time PC game (2005 or whenever) for $1 from direct to drive. Awesome game, if you haven't played it. Will probably play on your PC no matter how old it is at this point.
http://slickdeals.net/permadeal/34114/free-portal-pc-mac-game
Free Steam version of Portal for PC or Mac. Awesome, awesom game.