I have not scanned this whole thread, so I don't know what others have put in thus far...
My favorite classic was/is the first "Friday the 13th". I admit that when I first heard the ominous whisper of "ch-ch ah-ah" I was spooked. And I jumped when he flew out of the water at the end.
Other favorites are "Mary Shelley's Frankenstein" because of its grittiness. Branagh did not
try to make the film "super scary" - like the other incarnations; he retained the humanness that Shelley wanted and that is scarier than anything for me. Also, "Sleepy Hollow" is up there, but not so much for its fright factor as for its visuals. Beautiful film, wicked good villain.
I heard one guy say "The Descent" was the "scariest movie" he had ever seen. I liked it... mostly for the hot chicks.
I'm pretty skeptical with most films because I usually end up laughing. My dad and I used to sit up late when I was young and he desensitized me to most blood and guts. Now, sitting and watching an eye surgery on Discovery Health... :shiver: