Oblivion Game of the Year Edition is 50% off (9.99) at the Impulse/Gamestop
PC download store. It's today only though. 11/5/2011.
Link: http://www.gamestop.com/pc/games/oblivion-goty/91831
Good deal if you'd like to play it before Skyrim launches. It includes the
full game, The Shivering Isles expansion and the Knights of the Nine DLC.