*shakes head* Fine, I'll jump in on this...
Though, my knowledge of musicals may not be as vast as some of you (it's above average at least), I'll gladly share my opinion, based on what I think:
Alright, I think based on originality: [title of show]
Based on real-life, but in a funny musical kind of way featuring puppets: Avenue Q
Based on what's been said already: A fight between Rent, Gypsy and My Fair Lady
"We're all just children in a vast kindergarten trying to spell God's name with the wrong alphabet blocks."
- Tennessee Williams