When the “making of” is as compelling as the movie.
Right away Hearts of Darkness comes to mind. The ridiculously insane Apocalypse Now documentary shot by Coppola s wife. The one I was just watching was for Cameron’s The Abyss. No way would I have gotten through that flick as a crew member or actor. And another Coppola picture Bram Stoker’s Dracula had a fascinating look at both the effects they used and what happens when an actor and director butt heads.
I think I kind of miss DVDs because of this. It sucks you can’t stream movies with commentaries and supplemental material anymore.