Hi,
"Far Worse Things Await Man, than Death." Bela Lugosi in "Dracula"
I used to watch, and even keep track of all the Hammer Films for a long time. The Dracula and Frankenstein series with Christopher Lee and Peter Cushing, were very nice, even if the stories sometimes were stretched a few inches to revive the Count. But "scary" was not exactly my feeling then, because by that time, I had already been a serious student of "Gothic Literature" going as far back as Ann Radcliffe, and Horace Walpole!
Of the standard "horror" fare, none of them does me in. But there were a couple of films that fit the description of this thread. For me, it was called (had different names, btw) "The Legend of Hell House" with Pamela Franklin and that McDowell guy. It was very well shot and defined and well presented in the film. The scene with the cat, comes to mind ... I've seen things like that happen!
But Jean Luc Godard, introduced a few things that are used in these films ... sound out of whack with the film, and specially the effects out of sequence, and this became a big thing in many a horror film, however, none of these were as scary as many other things in film that were far superior in its effect than any horror film that I have ever seen.
Gaspar Noe's "Je Suis Seul" is probably the one film where it is not only disconcerting, it is very tough to even watch, and half the audience usually walks out, because it is so harsh and off its rocker ... and very tough to sit through. It's a gun shot, as loud as a shotgun that goes off at various times, and it's not designed, planned, or has any relation to the story of the film itself, which, btw, takes place in the characters head, non stop all the way to the end. And it is an insane attack on the French anything! AND, this is not a film for everyone! Like some of the weirdest and most avant-garde things EVER done, this questions your movie going left and right, and your entertainment ideas as well.
But nothing, in any film, has ever come as close as Mathew Gregory Lewis book, "The Monk" ... that can't even be filmed because it is so descriptive of the horrors in it. I don't suppose that many stories about WW2 are any better, and many movies showed it for the past 50 years, in their own way. When you come from that, horror film tends to look rather ... cardboard!