I finally had a chance to see Matilda the Musical recently and I'd recommend seeing it if musicals are at all your family's thing. (The show recently closed on Broadway, but a touring production continues to make its way across the country.) Based on the Roald Dahl novel, it's obviously kid-friendly enough for the youngsters and.... based on the Roald Dahl novel, it's obviously subversive enough for the no-longer-youngsters who tag along. The music and lyrics from Australian comedian Tim Minchin (who's also done the music and lyrics for the new musical of Groundhog Day) do a good job of matching Dahl's tone.
One of the musical's high points is "When I Grow Up," which features wistful lyrics that will sound quite different to kids' ears than to adult ears. Matched with some gorgeous choreography on swings, it's a moving moment in the show.
London Cast of Matilda the Musical - "When I Grow Up" [YouTube]