SF Signal links to a Buzzfeed list of horror films, none of which I've seen and only one of which (Suspiria) I have in my to-be-watched stack:
The Last House on the Left (Original)
Let’s Scare Jessica to Death
Black Christmas (Original)
I Spit On Your Grave
Alice, Sweet Alice
The Blood-Spattered Bride
Every time I think I'm making some headway, I come across another list!