Nexuiz proved to be a divisive proposition when it released on consoles earlier this year, and this slick CryEngine 3 FPS has finally returned to is PC roots. It's incredibly old-school, fast-paced, hardcore arena combat at its shiniest and most primitive, which isn't necessarily a bad thing, since it plays a lot like Quake III or Unreal Championship. I'm fairly certain that the PC will be a much more natural home for it, since the speed of the action is poorly suited to gamepads.
Caveat: I believe that this was cheaper in the Steam Summer Sale, which is sadly at an end. For now, though, here's a £4 saving.