Nintendo's gun peripheral has a slot for your Wiimote, and comes with Link's Crossbow training. It's no duck hunt, but it's really fun. The Good: High build quality, battery-less design, fairly accurate, Tommy-gun design of the Wii Zapper makes me feel like Wii Capone. Inexpensive, since it doesn't introduce electrics, depending on the Wiimote's exisiting buttons. Fun would be an understatement.
The Bad: The "A" button is awkward to hit, any sort of gangster sideways pistol action hurts accuracy. (Like in real life?) Unlike light guns, the Wiimote's aim does not literally translate into direct targeting; hence, aiming toward the edge of large screens makes accuracy dive. You're meant to shoot from the hip with this setup.