The 12 Days of Christmas are done; stop crying, time to get over it. Instead we welcome the 52 weeks of a new year and on the second week of 2013 my XBLA Sale gave to me - loads of 2K reductions including half price DLC on Borderlands 1 and 2.
The latest sale covers loads of 2K stuff that is currently available on XBLA, but the most co-op centric includes:
Borderlands - $9.99
• "New Revolution" - 400 MSP
• "Secret Armory" - 400 MSP
• "The Underdome" - 400 MSP
• "Zombie Island" - 400 MSP
• "Mechromancer Pack" - 400 MSP
If you don't already own Borderlands then $9.99 is a great price for one of the best co-op games of this generation. Both Borderlands 1 and 2 are 4 player co-op throughout the campaign and give hours of gibbing pleasure.
If the ultraviolence on offer with the folks of Pandora is not enough, could I recommend a sneaky single player offer? Either of the following games for 200 MSP is great value:
Axel & Pixel - 200 MSP
The Misadventures of P.B. Winterbottom - 200 MSP