Film: Jean-Luc Goddard's Masculin Feminin (1966)
This is by all means in my top 2 films by Jean-Luc Goddard. What is so great about this film was that it was one of the many that changed the direction of film in the 60s. It was independent, it was modern, and it was pop. Those words are so easily thrown around now, but at this point in his career, it was a revolution. The film was relative to the generation, and it wasn't a typical cinema classic with a typical happy ending.
Paul is young, just demobbed from national service in the French Army, and disillusioned with civilian life. As his girlfriend (Chantal Goya) builds herself a career as a pop singer, Paul becomes more isolated from his friends and peers ('the children of Marx and Coca Cola', as the credits announce) and their social and emotional politics.
If you've never seen the films of Jean-Luc Godard, I recommend starting here.