A 2nd or 3rd or 4th Wii-mote and nunchuck, depending on how many people you want to play at the same time. I've got the classic controller, the zapper and some other stuff, but rarely use them. If you want to play GameCube games you'll need a GameCube remote. The Wii-mote is the main controller. Some games need the nunchuck plugged into it.