Major Nelson has the full list of Xbox Live deals for Black Friday and Cyber Monday over here, but if it's simply the highlights you're looking for, look no further. Now through December 2, there's Skyrim, Dragonborn, and Dawnguard for half price; The Cave for $3.74; Tomb Raider for $14.99; and Mark of the Ninja for $5.09.
On Black Friday only, Rayman Legends will be half price, Diablo III will be 33 percent off, and Dragon's Dogma: Dark Arisen will be 66 percent off. Lastly, during Cyber Monday, there's Far Cry 3: Blood Dragon, Red Dead Redemption, The Witcher 2, Dark Souls, and L.A. Noire for 75 percent off, plus BattleBlock Theater (67 percent off) and Rayman Origins (50 percent off).
You probably know how you feel about most of these games already, so I'll just say give BattleBlock a chance if you like co-op platformers. It's one of the best of those in years.
Xbox 360 Game Store Black Friday sales [Major Nelson]