If you don't want to wait for the Halo: Master Chief Collection when it's released this fall, you can get a jump on checking out and catching up on most of the Halo games available - sans the first two. Right now Gamestop is offering Halo 3, Halo 4, Halo ODST and Halo Reach for the low low price of just $17.99. That's four games for $18.