33. Starsiege: Tribes (1998)
If you enjoy the Team Fortresses of the world, then you've gotta to get your hands on its spiritual successor, Starsiege: Tribes. The multi-player-only game was set in the 40th century (yes, that's 19 centuries from now) and allowed players to control one of four major tribes battling for control of the Great Human Empire. Heavy on story, the game also featured eight distinct weapons with which to blast an enemy's face off, including the Stormhammer, which shot a disc projectile that could stop someone in their tracks. One of the first titles that flirted with MMOFPS elements, it's still pointed to as an influential precursor to many of today's shooters.