Pacino has won exactly one Oscar for Best Actor in his entire career. Somehow, he didn't win it for either of what are considered to be his best performances: His role in The Godfather films, and his role in Serpico. Serpico is rougher around the edges than Coppola's crime epic, but there are few movies that showcase an actor's talents more fully than Serpico does for Pacino.
Serpico is based on a novel that, in turn, is based on the life of a real-world NYPD officer named Frank Serpico. In the 1960s and 70s, Serpico helped to uncover and report several instances of police corruption and brutality in the NYPD. No matter where he went, he found officers accepting bribes and breaking laws to further their own interests. It wasn't long before reporting on his fellow officers caught up with him, and he found himself targeted by his own coworkers.
The movie's take on these events is absolutely spectacular, and Pacino is electric in the lead role. His iconic look (the 1970s were a good look on Pacino) and simmering energy are impossible to forget. He exudes anger, resignation, and battered dignity in every frame. It's easy to overlook Serpico for Pacino's flashier roles, but if you really want to see him at his best, this is the film to watch.