Chinatown (1974)

When a private detective is hired to investigate a simple case of infidelity, he ends up discovering a huge secret network of corruption perpetrated by high-profile businesspeople, politicians and the police. This film, with a superb script and outstanding performances by Jack Nicholson and Faye Dunaway, earning several Oscar nominations, is a haunting and disturbing story about how greed becomes corruption in a system that values power and money over people.