Aliens vs Predator, developed by Rebellion, is an authentic take on the Predator and Aliens universes combining to make for a choatic clash of species.  The game includes three races including the marines, aliens, and of course predators.  The unique single player campaign is split up among the three perspectives and tells the story of each race.  Alongside this, the multiplayer portion of the game puts all three races against each other for chaotic multiplayer matches.