The Beyond

The Beyond is a 1981 horror movie I chose because of the Italian Horror Blogathon. It's directed by Lucio Fulci. First released in a cut version as Seven Doors of Death, an uncut version containing all the gore is currently available on DVD.

trailer:

1001 Misspent Hours calls it "a compositional masterpiece". DVDTalk says,

The gore is completely over the top and as arresting as an auto smashup. ... If the aesthetic of slasher horror is to investigate the ways a human body can be outrageously violated, The Beyond may be the front-runner.