From your description of what you like about School of Rock, I would unreservedly recommend 'Sky High' to you. Which is set in the high school where all the superheroes' kids go. :-> Cool powers, very well-written; the characters are all very human; plus, Bruce Campbell is the gym teacher, which is almost worth the price of admission by itself.

Very little pure slapstick, and lots of cute have-to-pay-attention worldbuilding humor. Plus, each of the kids with a 'useless' superpower gets to use it to help win the problem at the end.