Buff- I'm going to spin this one on you- how was "Wicked"? Was thinking of taking my 11 year old daughter- any good?
Wicked seems to really appeal to pre-teen and teenage girls, and my guess is she will love it (great story of being true to one's convictions, with strong women in the leading roles). Music is excellent. I have the OBC recording, and the Menzel/Chenowith dynamic is great. It's been around for a few years, so if you see it at the Gershwin in NYC, the cast will be people you've probably never heard of; but, it's still a spectacular show. I'm sure even a National Tour will be entertaining.
Regarding some of the other posts-
First, and I say this as a community theatre actor, I'd suggest checking out Off-Broadway venues (and even Off-Off) as well as the big Broadway musicals. These smaller venues are where some of the best non-musical theatre is. I have a weak spot for dramas.
Phantom and
Chicago have been around for a while, and you can usually get tickets for them at one of the TKTS booths in NYC. My suggestion is to use the one in Lower Manhattan (as opposed to Times Square), as it is less well-known, and you can get tickets for next-day shows (as opposed to TS, where the discounted tickets are only for that night). I'm not a huge fan of Webber, so
Phantom is not a fave (too much melodrama, even for a musical). Love Kander and Ebb, though, and
Chicago is the longest-running revival on the Great White Way.
As far as my suggestions for Broadway musicals, I might go with
Promises, Promises, as Sean Hayes and Kristen Chenowith are still in it, and
Next to Normal is a powerful show that is still around. I've also heard good things about
Memphis, but can't speak from experience on that one.
Enjoy, live theatre is great!!
Here is the Theatre Development Fund's website. They run the TKTS booths (discount tickets), and have good information on what shows are currently running:
http://www.tdf.org/
Click on the ticket services link, and then on info for the TKTS booths.