FPS, definitely. I just wish they would actually make it look like what someone would actually see. The thing I hate most is the character holding the weapon directly in front of their eyes, like in Fallout 3, wielding the Shishkebab in first-person, the blade which is on fire is held a few centimetres away from the eye, and the gattling gun barrels are right below the chin for christs sake. Also the characters have no peripheral-vision!
I like third-person shooters though, I like to see my character, not just their gun.