Everyone has commented on the film's plot and characters. What I would like to focus on is the details. The film (unlike the hopeless "Summer of Sam" by Spike Lee) captures in a very visceral and frightening way, the New York City of the 70's. From the opening scene with the lights from the porno theaters reflected off Travis Bickle's face to the end where the same theaters reflect in the mirror shows the oppressive terror that people felt about N.Y.C. and especially Times Square. If you watch it enough times, you'll notice that every scene has imagery that is stating something further. When Travis Bickle goes to meet up with the Jodie Foster character for the first time you hear church bells ringing in the background.  The Belmore cafeteria was a real life hang out for cab drivers and the scenes there are of every day life, hustling for a living. Of course, Robert DeNiro's portrayal of Travis Bickle is over the top but Travis Bickle is a character that, however guiltily people are forced to identify with (such as "Alex" in Clockwork Orange). Also, without bringing up the topic, the idea of the Vietnam vet that has become psychotic and lost his humanity (an interesting, although much lesser film would be Deathdream where a Vietnam vet who returns is literally a murderous zombie)and can only redeem it through "saving" someone else was just beginning to be explored at the time. The views of the checker cabs and the bygone Times Square as a squalid frightening place have been "disappeared".  Bernard Hermann's score of smooth jazz with the elements of rage suddenly boiling over in symphonic flashes is perfect for the movie. Screenwriter Paul Schrader is picturing a form of Dante's Inferno located on earth. Unlike the morally indefensible Deathwish (not to be confused with the above Deathdream), Charles Bronson's vehicle to stardom, Taxi Driver has a humanity in it. Travis Bickle is doomed by his own destruction, the ending showing that he is a ticking time bomb that is just being reset. Martin Scorcese, especially in combination with Robert DeNiro and Harvey Kietel has made many films that will stand the test of time but Taxi Driver is his masterwork.