I'm gonna say: Requiem for a Dream

Grave of the Fireflies

It is the greatest movie that I will never, ever, watch again.

Event Horizon

This may be a basic film-bro™ answer, but Oldboy is a good baseline for "kinda fucked up" but also "really really good". It's even better on the second viewing. I even recommend watching Spike Lee's misguided remake, because it makes you seriously appreciate the artistry behind what Park Chan-Wook was doing.

Kids

Very good, but very fucked up. Hit close to home in the lifestyle I lived as a teenager, just luck that things didn't end up like they did in the movie.

Midsommar…fucked up but a nearly perfect horror flic

"Requiem for a Dream." It's a great movie to watch once. I loved it, never have any interest in watching it again, and saw the book and thought, "Oh I liked that movie I'll grab the book." I started reading, and the first scene (as in the movie) is the junkie is at his mom's place trying to steal her TV to sell to buy drugs, and she's begging him not to because she wants him to get help, and he finds she's chained the TV up so he can't steal it as he's done before, and he gets really mad at her because she's chained the TV up so he can't steal it.

I thought, "Oh, right," and put the book down immediately. I have no interest in picking it up and reading the rest of it.

Hardcore Henry.

It's an easy answer. It's a very pulpy, violent, action film shot entirely in a real time first person vantage. A guy gets experimented on, escapes from the mad scientist, then goes on a 90 min video game quest to save his kidnapped wife. It's all explosions and train fights. It's the kind of thing you worry that people will respect you less for having enjoyed, but it's honestly an outstanding use of cinema and very fun.

Natural Born Killers. Though it really depends on threshold. Pulp Fiction is a better film imo, and some people would consider it "fucked up". But I don't really.

Pi by Darren Aronofsky

The ending to The Mist will follow me to my grave. Absolutely fucked up

A russian War Film called "Come and See" Three hours of watching a young boy being mentally wrecked by the atrocities of War. Gruesom, fucked up but incredible Film

I don't watch a crazy amount of movies but I loved The Platform (2019). It's a horror movie and and a revolting, elegant metaphor for class inequality.

A short stay in Switzerland. It's about an old lady who had a terminal illness and goes to Switzerland to end her life. It's incredibly depressing, there is a scene where she tries to suffocate herself with a plastic bag that I couldn't even watch

Grave of the Fireflies if you want to be depressed.

Nightcrawler if you want to be creeped out.

Basket Case (1982)

This movie is about twin brothers who try to find success in new york but one of the brothers is a murderous blob of flesh who lives in a basket.

Enter the Void. That movie stayed with me for months.

The Road.

Tough book. Tough movie.

Bridge to Terabithia

Jacob's Ladder

What a ride.

Deadgirl

Also I forgot the title... Vagina Dentata? Not good, more like silly.

The Mist. It started off ok, but the ending was just brutal, and I'm here for it.

Primer

The Lighthouse

Fight Club

Sorry, but that movie is fucked up. Awesome, but fucked up.

Off the top of my head:

• Nocturnal Animals
• Mother!
• The Killing of a Sacred Deer

The Skin I Live in 2011 (Antonio Banderas)

The brief synopsis below gives nothing away about how this film is so messed up.

A brilliant plastic surgeon, haunted by past tragedies, creates a type of synthetic skin that withstands any kind of damage. His guinea pig: a mysterious and volatile woman who holds the key to his obsession.

Sorry to Bother You 2018

I defy anyone to guess where that movie is heading.

Speak No Evil (2022)

I see all your movies and I give you Oranus
https://www.youtube.com/watch?v=XRQeTojVZlI
You're welcome

"A Serbian Film"

Young and dumb I watched a movie suggested by 4chan, I still have flashbacks over 10 years later of 1 scene from the movie.