Wicked (the musical and the book)
I saw it in St. Louis last year. It's not one of those plays/musicals that leaves you pondering the wonders on the earth, but it's good fun, especially (it seems) for young girls. The power lies in the vocal abilities and chemistry of the cast. And if you have not sung "Defying Gravity" or "Popular" at the top of your lungs at some point in your life, you are missing out.