#4 Halo 4
Bungie may have moved onto greener (or, given the color of Master Chief's armor, less green) pastures, but that doesn't mean that we've seen the last of Halo. Developed by newly minted franchise guardians 343 Industries, Halo 4 will kick off a new story arc for the Chief, which the studio has termed "The Reclaimer Trilogy".
For the time being, 343's playing their cards pretty close to the chest, but there are a few things we can safely bet on: Master Chief will shoot aliens, they'll shoot back, and at some point the Flood will show up and they'll all shoot each other. I don't know about you, but that's good enough for me.
