I'm also going to say Matilda. It's clever and moving. I think Cabaret is pretty close to being flawless IMO.
"The city seen from the Queensboro Bridge is always the city seen for the first time, in its first wild promise of all the mystery and the beauty in the world." - F. Scott Fitzgerald, The Great Gatsby
Gotta go with Pippin. I saw it last weekend and was amazed that the cast (almost entirely the original company) was still performing with opening night level energy. It was as fresh as when I saw it at ART.
It is a subjective question. Are you looking for laugh-out loud musical comedies, musical drama, London imports, adaptations of animated films, jukebox musicals, revivals of classic musicals or something else?
Pippin The Book of Mormon A Gentleman's Guide to Love and Murder Kinky Boots Matilda Cabaret Les Miserables The Lion King If/Then Wicked Once Bridges of Madison County Chicago Phantom of the Opera Newsies Cinderella Beautiful Jersey Boys Rock of Ages Rocky Aladdin Motown Mamma Mia!
Bullets Over Broadway - Haven't see Hedwig and the Angry Inch - same Violet - same