A tank game that uses the Wii remote to control one track and the nunchuk to control the other. You could use the Joystick to control the cannon, d-pad to switch round types, B to fire. You would then have A, C, and Z left over to do other functions.
It wouldn't have to be set with present tanks, as it could be futuristic, but other than using that control scheme I really don't care about what it is about.