Suspiria--Italian horror movie from 1977.
I know people say "you will either love it or hate it" a lot. In this case it's true. You'll either turn it off after the first ten minutes or you'll be transfixed to the screen.
Fun facts:
Entertainment Weekly rated it #18 in its top 25 scariest movies of all time, saying it had "the most vicious murder scene ever filmed", and it was rated #24 on the cable channel Bravo's list of the "100 Scariest Movie Moments".
In a poll of film critics conducted by the Village Voice, Suspiria was named the 100th greatest film made during the 20th century.
The film is also famous among filmmakers as the final feature film to be processed in Technicolor before the processing plant was shut down.
The Italian rock band Goblin composed most of the film's musical score. The score for Suspiria is considered a unique masterpiece regarded as a cult hit ahead of its time. Goblin frontman Claudio Simonetti went onto to form a heavy metal band, Daemonia.