• Self-Reference Engine by Toh Enjoe - this one stretches the limits of what a novel even is, it's not like anything else I've ever read

• The Freeze-Frame Revolution by Peter Watts - the inhabitants of a generation ship rebel against the controlling computer to take charge of their lives

• Transfinite Man by Colin Kapp - starts like a cloak-and-dagger detective novel, almost tropey, then goes off the rails into speculative science fiction

• Ubik by Philip K. Dick - a classic of surrealism, often referenced directly and indirectly by other works

• Permutation City by Greg Egan - ultimately an exploration of self-determination and personal trauma in a digital world - who do we become, if we have the freedom to be and do anything?

• The Emperor's Soul by Brandon Sanderson - in my opinion the most compelling of Sanderson's work

• Einstein's Bridge - a fictional exploration of the Einstein-Rosen bridge set in a timeline where the Superconducting Super Collider was not cancelled

• Unflattening by Nick Sousanis - philosophy in a graphic novel, an exploration of identity and self-knowledge

I think this is a rather cliche answer but since no one's mentioned him yet I'll put in a plug for Phillip K. Dick. I don't think I've ever encountered weirdness done as well as he does it. My favorites are Ubik, The Three Stigmata of Palmer Eldritch and Do Androids Dream of Electric Sheep? but he has a lot of books and as far as I can tell, they're all weird af.

or Spanish

Borges, if you haven't read any of his works yet.

Ever read Blindsight by Peter Watts?

Kelly Link's short stories are weird

• Magic for Beginners
• Get in Trouble

The first story is often not that weird, but she is fantastic at magical realism. They aren't scary though. I recall for instance one story being about a cannon.

checked Hiron Ennes, @AbouBenAdhem seems really interesting!

I haven't read those authors so I'm not sure if it's the same type of weird, but I recently read Hyperion which is both weird and good.

Gideon the ninth by Tamsyn Muir

Escapeology by Ren Warom

Weaveworld by Clive Barker

It's well-known and well-studied, but also infamous as a book few people ever actually finish because it is so weird: Gravity's Rainbow.

I finished it. I'm not sure what I gained by reading it, outside of having a better understanding of what an acid trip might feel like. Very weird.

Other mainstream but weird recommendations: Mexican Gothic (highly recommend this) and A Night in the Lonesome October

Asking around gave me this shortlist of suggestions:

• Agustina Bazterrica (in Spanish)
• Suzan Palumbo’s short fiction collection Skin Thief
• Saoirse Ní Chiaragáin’s Wax & Wane
• Ahmed Saadawi’s Frankenstein in Baghdad
• Kev Lambert’s You Will Love What You Have Killed

House of leaves is my all time favourite mindfuck horror literature. I just recommend going hard copy over ebook as the formatting is super important. I can't really describe it except to say I can see how Backrooms could be inspired by it.

Snowcrash by Neal Stephenson.

The story follows Hiro Protagonist—a pizza delivery driver in a fractured, hyper-capitalized future reality and an elite hacker/swordfighter in the virtual "Metaverse".

If you like that, his other books are fantastic, especially Cryptonomicon, Anathem, and Diamond Age.

I read a lot of anthologies, one I read recently was Dark Fantasies, which was a collection of folk, domestic and urban horror, that was pretty strange and scary, worth picking up if you find it.

Beyond the Aquila Rift.

Bunch of short stories 2 of which were made into the love death and robots series.

Leguin - City of Illusions …and all her other books. Check out old school The Machine Stops E.M. Forster. And Ministry for the Future- Kim Stanley Robinson and all of his other books.

Ack-Ack Macaque is pretty weird.

If you like it, there are 2 more books (I haven't read the 3rd yet).

Imajica by Clive Barker

Teleportasm by Joshua Millican

Air by Geoff Ryman

The Library at Mount Char by Scott Hawkins

A Touch of Jen by Beth Morgan (go in blind and stick with it)

14 by Peter Clines

The Hike by Drew Magary

Break the Bodies, Haunting the Bones By Micah Dean Hicks

Where They Wait by Scott Carson

The Works of Vermin by Hiron Ennes. Very reminiscent of Miéville and VanderMeer.

The Pandora Sequence by Frank Herbert and Bill Ransom. Some of the weirdest shit I've ever read, especially in The Jesus Incident where -

If you just want plain weird, George Saunders was pretty weird, but haven't read much of his.

I really like Izumi Suzuki's work, which gets pretty weird also, Gibson-esque I think.

I also love Ada Palmer's Terra Ignota series, weird in many ways but not sure in the way you mean.

Exordia comes to mind also, though I didn't enjoy it that much.

John Dies at the End was a wonderfully weird, semi-horror book I read in high school. Wikipedia describes it as comic Lovecraftian horror. Perfectly tasteless while also having really interesting plot hooks. I still think about that book even now, 15 years later. There's also a movie adaptation but they cut so much it's almost a completely different story.

For horror - Kathe Koja

I also think you would like How to Lose the Time War, not horror but trippy weird and so great.

This one is real weird

https://en.wikipedia.org/wiki/Hothouse_(novel)

I can only recommend the books of Nick Harkaway, very China Miéville-like. I started with the Gone Away world. In Spanish I recently read 'te di ojos y miraste las tinieblas' by Solà. 'El último día de la vida anterior' by Andrés Barba also gave me some Mariana Enríquez vibes. Finally, 'the seven moons of Maali Almeida' (this was nominated for the Booker prize iirc) was also a blast, made me think of Pedro Páramo at times.

i read a few from Carlton Mellick III, they're pretty weird. some are translated to spanish: https://carltonmellick.com/books/

other bizzaro fiction in english: https://www.bizarrocentral.com/bizarro-books/

for weird horror, my favourite that might just be weird enough for the question is The Seven Days of Peter Crumb by Jonny Glynn

I don't know any of the mentioned authors, but Blindboy Boatclub comes to mind instantly. He writes short stories and some of them can be really weird and some more like horror. I think he's got three books out now.

I haven't seen it mentioned yet so I'll throw in my rec: the spear cuts through water. You know how they say you need to know the rules to break the rules? This book is a masterclass in that. It does so many things that novels simply aren't supposed to... And the execution is flawless. The story is compelling, but I was most engaged with the way it was written. It felt like nothing else I've ever encountered - not because the ideas were new (nesting narratives, shifts in perspective, genre twists, etc) but because I've never seen so much of it executed so well together.

My all-time favorite novel is Blindness by Jose Saramago. I have only read it in English, but it was originally published in Portuguese as "Ensaio sobre a cegueira".

From Wikipedia: "It centers on an unexplained mass epidemic of blindness afflicting nearly everyone in a nonspecific city, and follows multiple unnamed characters as they navigate the social breakdown that swiftly follows."

The Stars Are Legion by Kameron Hurley

Super weird and fucked up SciFi and really good