Spend 1600 MSP by Nov. 22 and get 400 MSP back. There are a few steps to go through, so I'd recommend you check out this site for all the details:
http://www.xbox.com/en-US/Community/promotions/MGSHolidayOffer/home
Eligible Arcade Games
Eligible Game Add-ons
Eligible Avatar Items
http://www.xbox.com/en-US/Community/promotions/MGSHolidayOffer/home
Eligible Arcade Games
- Splosion Man
- South Park
- UNO Rush
- Perfect Dark
- Snoopy Flying Ace
- Defense Grid
- Magic the Gathering
- Banjo Kazooie
- Banjo Tooie
- Ikaruga
- Fable II Pub Games
- Braid
- A Kingdom for Keflings
- Rez HD
- The Maw
- Scrap Metal
- Alien Breed Episode 1
- Alien Breed Episode 2
- The Dishwasher Dead Samurai
- Duke Nukem 3D
- N+
Eligible Game Add-ons
- Forza Motorsport 3
- Mass Effect
- Fable II
- Halo 3
- Halo Wars
- Gears of War 2
- Alan Wake
- LIPS
- Crackdown
- Crackdown 2
- Banjo Kazooie: Nuts & Bolts
- Scene It
Eligible Avatar Items
- Halo Reach
- Halo 3: ODST
- Halo 3
- Gears of War 2
- Gears of War 3
- Crackdown 2
- Fable II
- Fable III
- Perfect Dark
- Toy Soldiers