'The Enigma of Kaspar Hauser' (1974)
Based on the true story of a young man who spent the first 17 years of his life never leaving his tiny room – and then became a public sensation when he finally ventured out into society – Herzog's cracked biopic would have felt offbeat and intriguing enough on its own. Still, the director thought he'd make things even more interesting by casting a 41-year-old street musician credited as "Bruno S." who had spent decades in and out of mental institutions and had never acted before. The result is one of the more odd and affecting performances in Herzog's movies – part guileless, part gimmicky and all genuinely WTF. A bold experiment that paid off in a big way.