J. Michael Straczynski, when writing the various Babylon 5 episodes, always had something going “straight to” hell, or some hideous creature that was “straight from” hell.
He had other words and phrases that he used all the time, but they escape me at the moment.
Tolkien really overuses “fell” as an adjective. It seems to pop up every couple of pages and is really distracting.
and, of course, if Robert Ludlum uses a variation of
" and the madness began " it is time to hurl the damn book at the wall
In that case:
vigintillion
subterranean
baleful
Samuel Beckett seems to have had a thing for deprivation.
Thomas Pynchon always refers to any quantity of things more than one as “a couple three”.
(Which proves, maybe, that not just those writers whose works are replete with stinkiosity suffer from this affliction.)
Don’t forget gibber!
More Dean Koontz: bougainvillea and fugue
CLive Barker likes to use immaculate in most if not all of his books. I don’t think I ever really saw that word until I started reading his books.
It’s been a while since I’ve read any Koontz, but I seem to recall characters (usually a woman or a child) “hugging themselves” a lot.
I only read the first Wheel of Time book, but to keep myself alert, I began a tally on the inside front cover of how many times food turned to ashes in someone’s mouth.
First time I read it, I took it literally and thought there was some evil magic afoot.
Edgar Rice Burroughs seemed to like vouchsafe.
I’ve heard the word used only once in normal conversation, but the person was deliberatedly using it as an affectation.
But ol’ ERB’s characters vouchsafed left and right. I’ve never seen so much vouchsafing in all my life.
At least one character in every Robert Ludlum book (or so it seems)is described as having an “aquiline” nose.
In all of Harry Turtledove’s books, whenever a tank explodes, it “brews up.” Whenever anybody smells food, their mouths “instantly fill with saliva.”
Turtledove’s characters agree with each other a lot. But they can never just say “Yes” or “That’s right” or anything simple like that. They’re all required to use some convulted variation of “Well, I’d say you’re wrong, but I’d be a liar, on account of I think you’re right.”
And yet I enjoy his books quite a bit, in spite of that.
Almost any Niven book will have references to filksongs.
I’ve read a ton of his stuff and I just KNOW there are some favorite words he reuses a lot, but I can’t think of any right now.
Another Lovecraft word:
gibbous
The moon is always “gibbous” in Lovecraft’s books. It means “nearly full”.
Neil Gaiman (writer of the “Sandman” comic) wrote an interesting parody on Lovecraft’s writing style and his penchant for “spooky” words in a short story called “Shoggoth’s Old Peculiar”.
Makes you wonder if he put out bids, doesn’t it? 
Quasi
It’s not a word per se, but he has used this to death in several of his novels. He writes of a character doing something in the past tense like “Not if he could help it, that was.” Y’all ever noticed that?
Quasi
William Boyd loves to use “farinaceous” and “rebarbative” meaning IIRC “Having a mealy or powdery texture” and “Tending to irritate; repellent” respectively.
Very unusual words but they feel good to say. He also likes ridiculous names for characters such as:
Flavia Malinverno
Morgan Leafy
Henderson Dores
I’ve been re-reading William Gibson’s “bridge trilogy” (Virtual Light, Idoru, All Tomorrow’s Parties) and am now chuckling each time he uses the word “lozenge”. He’s up to, if I recall correctly, seven times, and I’m halfway through ATP, so there might be more.
Heinlein uses “So” in so many contexts, it’s great.
Any of his novels, every one of his characters uses it at one point or another, always at the beginning of a sentence.
I guess that sounds kinda dumb, unless you’ve actually read his stuff and you know what the hell I’m babbling on about.