Trailer for a documentary chronicling the failed Nicholas Cage Superman movie. I always find stories about the production of movies (and failed movies) intriguing, so this looks interesting to me. The movie was pretty far along in pre-production before it got scrapped. Kevin Smith tells an excellent story about his time writing the script for the movie and dealing with producer Jon Peters who demanded a giant villainous spider at the end of the movie (which he finally got in Wild Wild West). Based on the trailer for the documentary it looks like they turned Brainiac into a giant spider to meet his demand.
There's also gems like this: