The Act of Killing (2012)

The Act of Killing (2012) breaks documentary conventions by having Indonesian death squad leaders re-enact their mass killings through cinematic genres of their choosing, a technique that is 50% more unsettling than a conventional historical account. Oppenheimer's film is faster than the average documentary in dismantling viewer comfort, forcing a confrontation with unrepentant evil. It won a BAFTA and an Oscar nomination, using 1,200 hours of footage to create a disturbing masterpiece about memory and guilt.