Here are some of my favorites:
"Live! Live! Live! Life's a banquet, and most poor sons of bitches are starving to death!" - "Mame
"If you know what you want than you go and you find it and you get it" - "Into the Woods"
"Life is just a bowl of cherries" - "Good News!" (or you could make the case for "Fosse")
I keep thinking of really bad ones. Like can you imagine if someone's quote was "Never forget, and never forgive"? LOL!
Then there's always your favorite and mine
"Defy Gravity!"
Madame Morrible: "So you take the chicken, now it must be a white chicken. The corpse can be any color. And that is the spell for lost luggage!" - The Yellow Brick Road Not Taken