The original Grimm's Fairy Tales were pretty dark. Hansel and Gretel murdered their parents after escaping the witch, the prince Cinderella married stuffed her step mom and sisters into barrels with spikes in the sides and rolled them down a long hill into a lake, etc.

You want to read a dark book? Read "The Castle", by Franz Kafka.

Books by EM Cioran, a pessimist with a dark sense of humor, faves include The Fall Into Time, The New Gods, A Short History of Decay and Anathemas and Admirations.

Interview with a cannibal - Günther Stapf (true crime)

The Wasp Factory, Iain Banks
The Trial, Franz Kafka

Currently reading (history/fact/non fiction) "Death's Acre" If you're into forensics, this is a very interesting book.

Call Me Evie - J.P. Pomare

The Dark Half - Stephen King

Sharp Objects - Gillian Flynn

The road, I think

Nathaniel... Can't remember the author

True Crime.
That’ll change your views on humankind.

Splatterpunk genre. Hands down.

F. Paul Wilson's Repairman Jack series is replete with monsters of the dark who want to destroy the universe and all that is light and good.

There is an entire series, also, by Douglas Preston and Lincoln Child, all about detective Aloysius Pendergast. The first in the series is called Relic. ALL of them are horrifying.

“The Kind Worth Killing” by Peter Swanson.

Books about women serial killers...they could be every bit as cold-blooded as male serial killers

Uncle Tom’s Children, Richard Wright.

The Woman in Black

Carrie

A clockwork orange

The handmaids tale

The company of wolves

Autobiography. An auzzie in big tiger prison in Thailand for heroin smuggling.. scary shit..