My school is doing the first amateur production of Thoroughly Modern Millie!! We open on February 8. (I'm in the ensemble) www.lvacademytheatre.org
So far Millie seems like it would be hard for a normal high school to mount - I'm at a performing arts high school. The score is kind of crazy for the musicians (I think we have 25 pit musicians, we start rehearsing with them tomorrow), and the set involves a turntable and platforms and stairs. There's a lot of dancing, especially tap, which can be hard to pull off if you don't have tappers (some of the best dancers in our show are having trouble with the tap because they haven't done it before). I'm probably just being snobby, but I don't know.
Beauty and the Beast, for sure. We did it last year (I was a napkin! hehe) and it was honestly one of the best experiences I've ever had. It's SO fun. We were lucky enough to have spectacular costumes and sets (total cost - about $100,000, I think), but I think it would be a good show to do even if you don't have the budget for something amazing.
"Sawyer, you're going out a youngster, but you've got to come back a star!"