Scorsese #5: Taxi Driver (1976)

It would be pretty easy to say this is the greatest psychological thriller of all time. The handful of movies that come close always have something a bit cartoonish to them, but what drives Taxi Driver is an unrelenting sense of disturbing realism. It's also aged well; out-there serial killers feel like freak occurrences, but unhinged, isolation-maddened, wannabe-super heroes are all over nowadays.