Technically, Basic Instinct is a giallo. And The Fourth Man is an exercise in horror that if Polanski put his name to Repulsion and that was horror, would definitley qualify as such.
Charles Laughton - who knows how many pictures he'd have directed had the audiences of the 1950's not been so fucking fickle. Night Of The Hunter is a wonderful southern gothic horror fable.
Gus Vant Sant made the much derided but endlessly fascinating Psycho
Paul Schrader inflicted Cat People on Ed Begley's arm and the viewing public (and technically Witchhunt was a sequel to the Lovecraftian Cast A Deadly Spell, but was pretty light on the horror).
That he is remembered as a horror director is perhaps testament to William Friedkin's ability as displayed in The Exorcist as it's only one for two horror pictures he actually made - if you don't count thriller Rampage (The Guardian being the other and he did a Tales From The Crypt as well, but then which director of the 80s/90s didn't!)
Francis Ford Coppolla made Dementia 13 and Bram Stoker's Dracula
Robert Siodmak was best known for moody noirs and german dramas, but he directed arguably the first slasher picture, The Spiral Starcase in 1946 and Son Of Dracula in 1943. The fact his brother was Universal writer extraordinaire Curt Siodmak was probably a help.
Richard Attenborough scared the tit's off puppet-fanciers with Magic
Bearded used-to-be-funny man Rob Reiner made Misery.
Ancient Brit Lewis Gilbert, of Shirley Valentine, James Bond and Ealing comedy fame, fucked up James Herbert's Haunted
Playwright turned director Neil LeBute is tackling the Wicker Man remake.
And William Wyler, director of such Academy Award winning pictures as Ben Hur and Mrs Miniver made psycho horror picture The Collector with Terence Stamp in 1965 during his twilight years.