top 5 takes less time, and in no particular order
DOOM 1&2
Goldeneye
Half Life 2
Quake 2
Perfect Dark
Honorable mention: Call of Duty games. Counterstrike. Team Fortress 2. Duke Nukem. Return to Castle Wolfenstien. L4D
I would not include most FPS released recently since they all seem to be "generic shooters". IE: rehashed shooting games with no originality or variety. Games that only are fun during multiplayer. I won't name any to avoid aggravating fanboys.
Bioshock would have made the list, but the vita-chambers removed all sense of danger from the game. Who cares if you die? You just get resurrected in a nearby chamber.
Also, when asking which FPS is the best, you have to differentiate between most original (usually older games) and best designed (usually newer games).
@ fuegonian
Resident Evil 4 is not an FPS
