I dont think there are a lot of people who like one or two of these movies and dislike the other one.Its either like them all,or dislike them all(as far as the people ive spoken to are concerned).
Anyway,coming back to Taxi Driver.For starters,De Niro was superb in it.Probably his best performance after Raging Bull.I found the manner in which Scorsese defined his character pretty entertaining.Its a slow movie yes,but it had its own intensity in a weird sort of way.The story wasnt too complex.It was pretty simple,yet it was presented brilliantly.