Too many to count...but my standard answer is usually "The Music Man" because I've liked it the longest.
Other faves would include "Beauty and the Beast," "The Lion King," "Miss Saigon," "Phantom of the Opera," "Damn Yankees," "Anything Goes," "Fiddler on the Roof," "42nd Street," "Les Mis," "The Sound of Music" and I would probably love "Avenue Q" since I like the soundtrack. XD
And West Side Story! I can't believe I've still never seen that movie!
Grrrrr and I want to see "The Producers" so badly. But I want to see Matthew Broderick and Nathen Lane in it.
I really haven't seen a musical I didn't like....'cept maybe Annie (I like the movie a lot better)....and I really wasn't too fond of Pippen either.