i totally second romeo et juillette..omg!! how much do i love "aimer"!!! my voice teacher (an AMAZING french-canadian baritone...if you're from montreal you've probably heard of him) and i did a duet of it and it was so awesome!!
but i'd also have to add "tick, tick...boom!" even though it's pretty well-known for folks on this board..outside it really isn't.
and "danny and sylvia" SO great!!!!
"grace, you're stuffed in a box getting rid of ass plaque. let's face it, this evening is a bust."