Don't you hate it when a movie or something else you like didn't do very well?

What are some great flops that have great worth?

Some examples I can think of are :

Van Gogh only sold one painting.
Moby Dick only sold about 500 copies during Melville's life.

Movies like The Thing, Wicker man and Peeping Tom

Albums like Pet Sounds, Paul's Boutique and Rodriguez's Cold Fact

Others?