A proper movie marathon deserves films that build on each other — each one raising the stakes a little, keeping the session alive well past the point you planned to stop. The documentaries that stay with you are the ones that make you question your assumptions before the film is finished — not about the subject, but about how you were looking at it.
There is nothing worse than picking the wrong movie for the mood. This curated list of documentary films for a movie marathon takes that risk off the table. Every pick here is that will mess with your mind — tried, tested, and worth your time. Happy watching.