Taxi Driver is an award-winning 1976 film directed by Martin Scorsese and starring Robert De Niro, Jodie Foster, Cybill Shepherd, Harvey Keitel, and Peter Boyle. I picked up a used DVD for cheap years ago but am just now getting around to watching it. It's considered one of the most culturally significant and inspirational film of its time. You can watch it at Paramount+ or with a free 7-day trial of Showtime.
The Guardian gives it 5 out of 5 stars. Spirituality and Practice says it's "A compelling and unsettling film exploring many of the fears, aches, and dislocations of contemporary urban life. " Roger Ebert gives it a full 4 stars and calls it a great movie and "a brilliant nightmare". Empire Online gives it 5 out of 5 stars and closes with this: "The blend of Schrader's script, Scorsese's direction and De Niro's performance is both riveting and unnerving. A film that will stay with you forever." Rotten Tomatoes has a critics consensus score of 96%.