Taxi Driver (1976)

Travis Bickle, a disturbed Vietnam War veteran suffering from chronic insomnia, navigates the seedy underworld of 1970s New York City as a nighttime taxi driver. Isolated and socially awkward, he becomes increasingly obsessed with the moral decay he witnesses on the streets, fixating on ridding the city of its filth. As his mental state deteriorates, Travis arms himself, planning a violent reckoning that will leave a lasting impact on those around him.