$20 off Halo 4 ($39.99)

Retailer: Gamestop

Platforms: Xbox 360

Link: http://bit.ly/lr0Nqi 

Master Chief and Cortana are back with all of their friends in this year's edition of Halo: Adventures in Space! Seriously though, if you haven't played Halo 4 yet and even have a moderate interest in the series, you owe it to yourself to pick this up while its on sale. 343 does the impossible and bests Bungie at their own game in nearly every category imaginable and with tons of Spec Ops content and DLC coming down the road, it's an investment that will lead to a year's worth of happy alien shooting fun.