In no particular order other than the order I thought them up in:

Planetside 2
Tribes 2
Quake 3 Arena
Unreal Tournament (1999)
Deus Ex: HR
Team Fortress 2
Battlefield Bad Company 2
Half Life 2
Left4Dead
Tribes: Ascend

Honorable mention:
Section 8: Prejudice. Pity the game never took off, because I really did like the shooting in it.