I'd say pretty much all of the dances in WEST SIDE STORY. The best ever. Period.
Others worthy of note:
Let's Face The Music And Dance from FOLLOW THE FLEET: Fred and Ginger, wow.
Everything Old Is New Again from ALL THAT JAZZ.
Money Makes The World Go Round from CABARET.
Anything involving the Nicholas Brothers.
"If they can get you asking the wrong questions, they don't have to worry about the answers." Thomas Pynchon, GRAVITY'S RAINBOW
"Reality is that which, when you stop believing in it, doesn't go away." Philip K. Dick
My blog: http://www.roscoewrites.blogspot.com/