Not sure if this would be appropriate or not...but my son loves a band called Go Fish. They are christian--so if that's not your thing, maybe not. But it's good music (pop rock style, not obnoxious little kid style like Barney, LOL), no "nasty" lyrics, and some of their songs are down right danceable. (DS takes a hip hop dance class at his school, and his teacher uses one of their latest CDs called Snazzy for them a lot.)
It's hard to find good stuff for kids, isn't it? Other things DS likes are any Kids Bop, and some stuff from Radio Disney--which I still edit if an inappropriate song comes on.