im inclined to say heathers because the movie is the all time number one top film in the entire universe but the musical is just really different lul i dont exactly have the same passion for it. ive seen it thrice though. most recently in august during the uk tour
i saw beetlejuice recently and it was so cool dude like the set work was out of this world. id watch it 100x over if i could, probably my favorite until something else tops it