Well, as a past pc gamer my top looks a bit different. :D
1. Counter-strike&TFC
3. TF 2 (360)
4. Quake 2
5. Unreal tournament
6. Quake 3
7. Cod 4 (pc)
8. Halo 3
9. Bioshock (360)
10. Gears of war (kinda fps)
I don't usually like single player shooters, but I loved bioshock and gow on 360. :) Online/lan multiplayer is what makes a fps great.