Who doesn't like a good first-person shooter? Console favorites such as “Halo” and “Call of Duty: Black Ops II” are all the rage right now. Unfortunately, these titles aren't yet available on Facebook, but you can easily take up arms with the next best thing — “UberStrike.” This beautiful first-person shooter from Cmune features a number of multiplayer options, including guns, maps and armor, as well as the ability to log in with your friends for clan battles and tournaments. You can also make your own hero from scratch, be it a well-armed zombie or a full-blown post-nuclear scientist, inspired by the "Fallout" franchise. With more than 10 million players and rising, the competition is here in spades.