The only correct answer... mouse + kb obviously.
Everything else is cancer in fps especially lol

Depends on the game. Mouse is usually the best by far, but different kinds of touch interfaces can be better for some sorts of games. There's probably some other methods that work better than mouse in certain situations, but I'm not too familiar with them. I guess a combination of different methods could probably work the best in certain situations.

Right analog stick.

Mouse + keyboard, Wiimote, Gyro-aiming and Right analog stick, in that order.

Good ol' analog stick. I tried Keyboard + Mouse a couple of times, but it was frustrating to use.

PS move on Killzone 3 was pretty slick but I don't know in which category it falls.

This guy gets it :)

Whatever you're not familiar with is probably frustrating to use. Takes some time to get used to different aiming methods.

Mouse or gyro-aim. Can't do sticks anymore.