4. Taxi Driver (1976)
Possibly the greatest character study ever put to film, Taxi Driver will forever be regarded as one of the best films ever made with many people (myself included) calling it Scorsese's best. The film does a perfect job of placing the viewer in the mindset of its protagonist by way of Scorsese's directorial decisions and De Niro's flawless performance. As the film progresses, you begin to feel as if you have an understanding for Travis and you begin to sympathize with him even as he's planning and committing some truly horrific acts. Taxi Driver draws you into its world of a seedy New York from the first frame of the film and Bernard Herrmann's amazing score highlights the scenes bringing out their full effect of alienation and frayed psychosis. There is not one frame of Taxi Driver that is out of place and I can truly say it's a perfect movie from start to finish. It just gets more and more rewarding with every repeat viewing.