Medal of Honor: Heroes 2 has a Zapper mode as well...it works pretty well
Essentially you play through the single player campaign in an "on-rails" shooter.
Link's Crossbow Training is cool too
I have read lots of reviews about the zapper, most of them negative. Personally, after using it, I think it's kinda cool. The only complaint I have with it is that you wrap the nunchuk cord in the handle of the zapper, and if you leave it in there for a while, the cord will get all bent up...kinda like wrapping ps2 cords around the controller...
I'd say if you're thinking about it...just get it...it's only twenty bucks...and if you don't like it, at least you got another "Zelda" game