I've been re-reading Maldoror by the Comte de Lautreamont and it's still the most relentlessly evil and hallucinogenic piece of literature available. Read this and it's like peeling the skin off of mankind uncovering tender sex with sharks, mythical beasts, murder and mayhem, cannibalism, infanticide, live burials, fly swarms, hermaphrodites and a whole host of liminal characters, torn apart by their own depravity.
Here's a little taster:
"One should let one's nails grow for a fortnight. Oh! How sweet it is to brutally snatch from his bed a child with no hair yet on his upper lip, and, with eyes wide open, to pretend to suavely stroke his forehead, brushing back his beautiful locks! Then, suddenly, at the moment when he least expects it, to sink one's long nails into his tender breast, being careful, though, not to kill him; for if he died, there would be no later viewing of his misery. Then, one drinks the blood, licking the wounds; and, during the entire procedure, which ought to last no shorter than an aeon, the boy cries.... "
If you're interested in Surrealism then this book kicked the whole thing off and was deified by Andre Breton and the early Paris mob. It's also the source of perhaps the most beautiful simile ever written: “As beautiful as the chance meeting on a dissecting-table of a sewing-machine and an umbrella..." which later became the title for Nurse With Wound's debut album.
It's not particularly easy to read (the first few pages are a bit tiresome),it makes almost no sense whatsoever and it can get quite nauseating at times but it's one of the very few works of true art in literature and you should read it.