From now until January 31st, the following 2K and Rockstar content is on sale for up to 50% off:

Borderlands - Zombie Island of Dr Ned Regular Price: 800 Sale: 400 Save: 50%
Borderlands - New Revolution Regular Price: 800 Sale: 400 Save: 50%
Borderlands - Secret Armory Regular Price: 800 Sale: 400 Save: 50%
Borderlands - Underdome Regular Price: 800 Sale: 400 Save: 50%
Bioshock 2 - Minerva's Den Regular Price: 800 Sale: 400 Save: 50%
Bioshock 2 - Sinclair Solutions Regular Price: 400 Sale: 200 Save: 50%
Bioshock 2 - Rapture Metro Regular Price: 800 Sale: 400 Save: 50%
Bioshock 2 - Protector Trials Regular Price: 400 Sale: 200 Save: 50%
Mafia 2 - Jimmy's Vendetta Regular Price: 800 Sale: 400 Save: 50%
Mafia 2 - Joe's Adventure Regular Price: 800 Sale: 400 Save: 50%
Sid Meier's Pirates! Regular Price: 1200 Sale: 600 Save: 50%
Bioshock 2 Prototype Big Daddy Outfit M Regular Price: 320 Sale: 160 Save: 50%
Bioshock 2 Prototype Big Daddy Outfit F Regular Price: 320 Sale: 160 Save: 50%
Bioshock 2 - Big Sister Helmet Regular Price: 160 Sale: 80 Save: 50%
Borderlands - Bandit Mask Regular Price: 160 Sale: 80 Save: 50%
Borderlands - Moxxi Hat Regular Price: 160 Sale: 80 Save: 50%
Mafia II - Fedora Regular Price: 160 Sale: 80 Save: 50%
Mafia II - Vito's Outfit M Regular Price: 240 Sale: 120 Save: 50%
Mafia II - Vito's Outfit F Price: 240 Sale: 120 Save: 50%
NBA 2K11 - NBA 2K11 Slam Dunk Regular Price: 240 Sale: 120 Save: 50%
Los Angeles Lakers NBA Jersey M Regular Price: 240 Sale: 120 Save: 50%
Los Angeles Lakers NBA Jersey F Price: 240 Sale: 120 Save: 50%
Boston Celtics NBA Jersey M Regular Price: 240 Sale: 120 Save: 50%
Boston Celtics NBA Jersey F Regular Price: 240 Sale: 120 Save: 50%
Axel & Pixel Regular Price: 800 Sale: 400 Save: 50%
The Misadventures of PB Winterbottom Regular Price: 800 Sale: 400 Save: 50%
GTA IV - The Lost and Damned Regular Price: 800 Sale: 400 Save: 50%
GTA IV - The Ballad of Gay Tony Regular Price: 1600 Sale: 800 Save: 50%
RDR Undead Nightmare Collection Regular Price: 1600 Sale: 1000 Save: 38%
RDR Undead Nightmare Pack Regular Price: 800 Sale: 400 Save: 50%
RDR Legends & Killers Regular Price: 800 Sale: 400 Save: 50%
RDR Liars & Cheats Regular Price: 800 Sale: 400 Save: 50%
MC LA South Central Ultimate Content Pack Regular Price: 1000 Sale: 500 Save: 50%
GTA San Andreas Regular Price: 1200 Sale: 600 Save: 50%
Max Payne Regular Price: 1200 Sale: 600 Save: 50%
Max Payne 2 Regular Price: 1200 Sale: 600 Save: 50%
RDR - Armadillo Undead Outfit M Regular Price: 320 Sale: 160 Save: 50%
RDR - Armadillo Undead Outfit F Regular Price: 320 Sale: 160 Save: 50%
RDR - Lasso Regular Price: 240 Sale: 120 Save: 50%