Resident Evil: Dead Aim would be great with the rev controller/nunchaku. In the PS2 game, you had to move around with the d-pad on the back of the GunCon, or use two controllers - a dual shock for movement in third person, and light gun to shoot in first person. It was still fun and an interesting take on the RE series, though. Hopefully we'll get another on the revolution. If not Resident Evil, I'm sure there will be plenty of others.
...oh, and I'd love to see a Panzer Dragoon lightgun/rail-shooter game on the rev, too... (sega plzplz!)