I personally loved Spamalot. I am a fan of the movie, and while things are definetely different, it is still an amazing and hysterical show.
I've heard nothing but good things about Color Purple and Mary Poppins, and Spring Awakening is my new favorite obsession. I'm actually seeing it on Wednesday, so I will let you know how it is.
Anywho, for the touristy things, there is the usual: empire state, statue of liberty, ellis island, ground zero, rockafellar center, times square, etc.
If you like shopping, go to the South Street Seaport. HUGE mall, and tons of outside shops and such. I don't exactly know where it is, but I know it is relatively close to the Brooklyn Bridge (there is a gorgeous view of the bridge from the back of the Seaport).
Times Square is awesome. I love to just walk around, going into random shops along the way. There is a Hershey's store, which as you walk by it, you can smell yummmmy hershey's chocolate... and the huge ferris wheel inside the Toys R Us is really cool. Expensive and sometimes crowded, yes, but still really fun.
As for food... Hard Rock and Planet Hollywood are cool... Ellen's Stardust Cafe is fun, as the waiters sing for you. For really good pizza, try John's Brick Oven Pizzeria. And for realllly good Italian food (family style), try Tony DiNapoli's. (AMAZING pasta. and really good Ceaser Salads.)