Genuinely scary (non-FPW) books I've enjoyed...
Sarban: THE SOUND OF HIS HORN - nightmarish vision of an alternative future where the Nazis won, and genetically-altered humans are hunted for sport.
Ray Bradbury: THE OCTOBER COUNTRY - Good ol' Unca Ray could scare the bejeezus out of you when he wanted to. Some of his best, and most frightening, work.
Kingsley Amis: THE GREEN MAN - made into a not-so-bad BBC adaptation with Albert Finney, the original is great. The scene where God appears to the protagonist is one of the most metaphysically frightening scenes in literature, more like an unsettling visit from Internal Security than a holy visitation.
James Blish: DAMNATION DAY - an omnibus collection of two novels, wherein a nihilistic arms manufacturer pays a black magician to release all the demons of Hell for one day on Earth. Classic scenes where the Pentagon tries to deal with the fact that Dis, the capital of Hell, has arisen in the middle of Death Valley.
William Peter Blatty: THE EXORCIST - like most ex-Catholics (I no longer believe in hell, but know that's where I'm going), this novel struck some nerves that vampires and werewolves can't reach.
T.E.D. Klein: THE CEREMONIES - with this, a collection of 4 novellas (DARK GODS), and a handful of short stories, Klein revisited Lovecraft turf and combined it with the horrors of urban living. Sadly, he hasn't written much since.
Richard Matheson - Pretty much everything, but especially I AM LEGEND.
John Christopher: NO BLADE OF GRASS (also published as THE DEATH OF GRASS) - a worldwide virus destroys all grain (wheat and rice included), and civilization quickly begins to collapse. The ordeal of a small group of families trying to make it to safety through the collapse of public order in Great Britain terrified me when I first read it.
Shirley Jackson - THE HAUNTING OF HILL HOUSE: Great novel, great (first) movie adaptation.
Philip Wylie: THE DISAPPEARANCE - Wylie was a popular curmudgeon in the fifties and sixties, all but forgotten now. This novel depicts as great an apocalypse as you could imagine: all the women disappear from the world of men, and all the men disappear from the world of women.
Fritz Leiber - OUR LADY OF DARKNESS - Fritz couldn't write a bad story. Great San Francisco-based novel; also check out CONJURE WIFE, YOU'RE ALL ALONE, and any anthology of horror, sword and sorcery, or science fiction.
M.R. James: GHOST STORIES OF AN ANTIQUARY - a master of horror by suggestion.
H.P. Lovecraft - THE COLOUR OUT OF SPACE, CALL OF CTHULHU, THE WHISPERER IN DARKNESS
Stephen King: 'SALEM'S LOT, THE SHINING, THE STAND; THE DEAD ZONE is genuinely sad, a modern tragedy.
Robert Heinlein: THE PUPPET MASTERS: amazing combination of horror, spy thriller, science fiction, and anti-collectivist statement. Often ripped-off, never equalled.
Isaak Babel: RED CAVALRY (also printde as LYUBKA THE COSSACK) - not horror per se, but the dispassionate, staccato view of the horrors of war as represented by the Polish-Soviet conflict is genuinely terrifying.
Andrew Vachss: the Burke Series, and also stand-alone novel SHELLA. Highly Recommended.
"Flow with the Go."
- Rickson Gracie