Keyboard + Mouse for shooters, sir. You definitely won't regret building those motor skills. As for controllers, it entirely depends on what the game supports. For simmers like myself multi controller support is one of those unicorn features only a few titles have. Most games at least support one controller at a time (in addition to K+M) just a matter of configuring your stuffs. I'm honestly hard pressed to find games where a K+M isn't a superior control scheme. Sports (not counting auto racing) games, maybe adventure platformers... fighting games (get a stick!) ...