M (1931)

Fritz Lang made a film about a child murderer in 1931 that's more structurally sophisticated than most thrillers made ninety years later. Peter Lorre's performance is the definition of skin-crawling — pathetic and terrifying at the same time. The kangaroo court scene at the end raises questions about justice that nobody has answered yet. A film that belongs in 2026 despite being nearly a century old.