Any film by Paul schrader is ok with me.  I love his work.  This film gives me chills even to think about it. I have the soundstrack and can see the film in my head as i listen to it.  I also bought the book. "The making of Taxi Driver."  It is  amazing.  I saw this film in the theaters  when i was 16 in high school.  I am not sure if back then i totally understood it.  It took a few viewings as I got older.