Looking for a FPS with a good single player campaign. Suggestions?

[Hisiru]

-Bioshock series (everything in this game is good for me)

-Far Cry 2 (GREAT game, you will love it!)

-Metro 2033 (incredible atmosphere)

-Fallout 3 (mix of RPG and FPS)

-S.T.A.L.K.E.R series (mix of RPG and FPS)

-Borderlands (yes, again, mix of RPG and FPS, but you can also play online multiplayer)

-COD games (Modern Warfare, Modern Warfare 2 and Black Ops)

-Half Life series (very good storyline)

-Deus EX series (excelent gameplay)

-System Shock

-The Chronicles of Riddick series