RELOAD!!!

Gran Turismo.

Unreal Tournament.

My favorite is Halo. Halo 3 specifially is the pinnacle of console fps gaming. Halo: Reach and Halo 4 were, for me, step backs though multiplayerwise. Still great games, but I don't really like armor abilites or random weapon spawns.

I wish more console fps games had a feature similar to forge. It just adds so much replayability. Not only that but the level of customization of game modes is crazy for a console game. Those are two things I wouldn't mind if other developers copied more often.

I don't have too many friends that play PC shooters, so I don't get as much enjoyment out of them, but my favorite would probably be Left 4 Dead 2. If i can manage to find a good team to play as and play against versus mode is ridiculously fun.

No Goldeneye or Perfect dark for the 64??????? For console it would have to be Goldeneye, and for PC Half-life/counterstrike.

Its Half Life for me. I think it provided the following:

It created a new way to tell stories in FPS games, traditionally it was done by loading screens prior to HL.
The open nature of the HL engine spawned multiple mods that have become massive success in their fields. HL spawned Team Fortress, Day of Defeat and Counter Strike, some of the best multiplayer experiences ever created and they laid down a lot of framework for the modern day FPS.
HL2 launched Steam, the first really successful digital Download service on PC's.
HL2 introduced the source engine which powered 5+ years of great games and it also introduced physics into the FPS world.
They moved character interaction to a new level with Alyx.
It ultimately spawned a little mod that came to be the game Portal, which once again pushed new boundaries.

The above is just off the top of my head but there is so much more that can be said and the games happened to also be great at the time too. This for me its the best/greatest/most important series of FPS games.

P.S. Massively biased as I did spend 2 years solid playing TF2 online

It has to be Doom. It was the first real must play FPS. It had blood and guts albeit pixelated. I fell in love with it when I first played it and I can still really enjoy it now. Replayed the first game a few weeks back and I still remembered all the secret areas. Great game

Since Gran Turismo isn't up there, I guess I'll vote Killzone.

I prefer Killzone.