So far, unanimous. Keyboard and mouse for FPS.

I will say, however, that I cannot (or, refuse to) play -most- third person games with keyboard/mouse combo. If the game supports keyboard only (like FFXI), I'll do it if I can get comfortable with it. Otherwise, with games like Dark Souls and Kingdoms of Amalur and Dragon Age (etcetera), I'll use a controller to play. It just makes more sense to me, because it feels more natural in that instance. Hotkey a few things to various keys on the keyboard, and then use a controller for everything else.

Ever tried a racing game on PC without a controller or a driving wheel? Asking for nightmares.