Sidney Lumet directed this courtroom drama in a genuinely astonishing feature debut. Before 12 Angry Men, he had done a lot of TV work, but this move into movies set the bar extremely high for the rest of his career.
The premise is simple: 12 unnamed jurors debate the verdict in their murder case, and Henry Fonda's #8 is the only one willing to give the defendant the benefit of the doubt. Over the course of a tense, sweatily-claustrophobic afternoon, he gradually enables his fellow jurors to see the situation from a fresh perspective. Masterful stuff.