Freaks Bride of Frankenstein Psycho Peeping Tom Texas Chainsaw Massacre The House on the Hill Evil Dead. pt 2 Nightmare on Elm Street. pt 5 The Feelies
The Ring(US version) - Scared the hell out of me. When that crazy bltch crawled out of that t.v., I was terrified. The Shining Texas Chainsaw Massacre(the new version)
Don't know if I have a favorite, but I like the Evil Dead series. I'll include Army of Darkness in that, but I think that's more along the lines of a comedy or possibly a sci-fi/action movie. Or all three, but definately not horror. Another good horror movie was the first Texas Chainsaw Massacre. I have yet to see the new one.
A quick ten movie list, but a quality one: Nosferatu (1922 silent version, F.W. Murnau) The Phantom of the Opera (1925 silent version, Lon Chaney) Dr. Jekyll and Mr. Hyde (1932, Federic March won an Oscar) King Kong (1933, has to be here, period) The Bride of Frankenstein (1935) Werewolf of London (1935, dated but fascinating and exotic, not over-glossy like 1941's The Wolf Man) Dead of Night (1945 British film, best "omnibus" picture ever) The Thing From Another World (1951) Godzilla/Gojira (1954, the original Japanese version, not the Americanized one with Raymond Burr. Don't laugh at this selection unless you've been fortunate enough the have seen it.) The Abominable Snowman of the Himalayas (1957 Hammer Films with Peter Cushing, greatly under-rated with a brilliantly intelligent ending) Interestingly, all are black-and-white (except for "Phantom"s two-color technicolor masquerade scene.) You can have all (and I mean all) of the contemporary "horror" movies.
I'm going to take the original question literally. Thus here are my favorite films that more or less fall under the category of "scary," even if none of them are specifically the "scariest" I've ever seen. Carrie Salem's Lot The Woman in White Something Wicked This Way Comes The Ring Psycho The Shining Sixth Sense Poltergeist The Others The Evil Dead Jaws
I thought I'd add to my movie list some terrific television episodes: The Howling Man - from "The Twilight Zone" Pidgeons From Hell - from "Thriller" The Caterpillar - from "Night Gallery" The Glass Eye - from "Alfred Hitchcock Presents" Corpus Earthling - from "The Outer Limits"
I forgot one! Island of Lost Souls (1933, with Charles Laughton, based on H.G. Wells "Island of Dr. Moreau")