I enjoy musicals if I like the music, but in general I find the stories are pretty thin or not well developed, probably because so much time is spent singing and dancing around, making plot development and dialogue more limited.
I like Sweeney Todd, as I really like Sondheim's music, and it has a nice atmosphere to it.
I'm currently playing in West Side Story at my university, though it's kind of crazy as I am only advanced on flute/picc and not a true doubler, so I am splitting a part with a sax player.