Ditto except i have Perfect Dark in Halo 2's place

Right now....

TF2
HL2 (including sequels/expansions)
UT2k4
Perfect Dark
Goldeneye

PS -Maybe its just me, but it seems kinda silly to list a game and its sequels... With the FPS genre you pretty much like the series or you don't. In other words we know you guys really like Halo, lump them together(see above) and let us know what other games you like.

1) Goldeneye
2) Battlefield 2
3) Half-Life series
4) Halo series
5) Perfect Dark

Special mention to Doom and Wolfenstein 3D as it was these games that first got me into FPS's.

After recently selling my N64 I miss Goldeneye and Perfect Dark, I really hope they are released on the Virtual Console or XBOX Live.

1.Goldeneye
2.duke nuken 3d
3.wolfenstien
4.perfect dark
5.counter strike source

1. Goldeneye 007
2. Doom

(I can't place the next in any particular ordering)

Timesplitters 2
F.E.A.R.
Possibly Call of Duty heh.

1. GoldenEye
2. Perfect Dark
3. Time Splitters Series
4. Doom
5. Half Life

Half-Life
Hexen (!)
Call of Duty (the original)
Half-Life 2
Timesplitters 2

Operation flashpoint( all addons and sequel A.R.M.A.)( and i love also the mods for national armies)

return castle wolfenstein

ghost recon

doom 3

goldeneye

ps:

only one game from console,but in my opinion consoles aren't good platforms for fps... 

1) mouse and keyboard

2) mods

3) online  

pc is superior on these.

Half Life
Golden Eye
Half Life 2
Bioshock
Far Cry
Star Wars Republic Commandos (The dialogs make laugh a lot)

in no order

Halo
Bioshock
Goldeneye
half life
gears of war(i know it's not a first person shooter,but i don't care. it's awesome!)