I loved this documentary about Alejandro Jodorowsky's quixotic quest to make a movie based on Frank Herbert's Dune in the mid-70s. In this 2014 film, we get to see and hear Jodorowsky, an energetic and charismatic octogenarian, describe with great passion his dream to combine the talents of Moebius, Salvador Dali, Mick Jagger, Orson Welles, Pink Floyd, H.R. Giger and top special effects artists to produce what has been called "The Greatest Movie Never Made." There's one scene in the film where Jodorowsky is describing a trippy space flight scene, accompanied by Moebius' stunning storyboards, which momentarily lets you see the mind-blowing awesomeness of a movie that exists only in the mind of Jodorowsky.
Right now, Amazon has the Blu-Ray/DVD of Jodorowsky's Dune for just $(removed)