Creepy Pasta in general, but specifically this one. Writing a scary story centering around a computer with the intention of posting it on the internet is the horror equivalent of throwing bull's-eyes by standing an inch away from the dart board.
Pick a Creepypasta. Any Creepypasta. Proof positive that an amateur is far more dangerous than a professional.
On a couple corners of the internet, people from wooded areas on the east coast of the U.S. (such as Virginia and West Virginia) are reporting seeing the phrases "OKEE" and "33>10" graffiti'd on various walls and such. It all seemed rather harmless until someone on 4chan's /x/ (Paranormal) board mentioned a story about the "avatar of the dead god Okee" digging up corpses in West Virginia.
Try reading the entirety of this and see if you can ever sleep again.
There is a retconned "Holder of Sacrifice" story. Imagine seeing everyone you know screaming and in torture, as well as killing the Holder, who after you kill turns out to be a loved one, then waking up in a graveyard, "exactly six feet over" him or her.
Oh yeah, there is also a fan made game of it as well. Have fun!
A fairly recent creepypasta where scientists try and communicate with god. By depriving an old man of all his senses. He can't even feel pain, to the point where he tries to claw out his useless eyes just to feel something. Even worse is the very end "I have spoken with God, and He has abandoned us".
NES Godzilla Creepypasta: The entire thing, from start to finish, as it escalates from unusual, to unsettling, to frightening, to downright malevolent. Every level manages to be HONF in its own distinct way, but special mention goes to Hellbeast.
That's nothing. The real terror is when the narrator finally reaches the end of the game. Up until this point it's just been weird though there's clearly something unnatural, but at least he chose to keep going. In the climax, he's finally put face-to-face with the Hellbeast who literally paralyzes him into his seat and doesn't even so much as allow him to pause. Worse still, the narrator actually feels any damage inflicted upon his character in the game (which includes flame attacks) and, when he loses, the Hellbeast tries to stop his heart, and almost succeeds. The fact that the Hellbeast or "Red" as it's called, supposedly knew the narrator before he started playing the game and was somehow behind the death of his girlfriend is also quite unnerving.
The most terrifying ones are the ones that are written in the style of scientific documentation (like Russian Sleep Experiment or SCP Foundation), because they're just so realistic. The fact that the comments section is usually filled with people asking "omg is this real???" takes a bit of a layer off the horror, though.
Speaking of the Russian Sleep Experiment, it's one that finds its way into most of the top 10 lists, and is regarded by some as the scariest Creepypasta ever. It goes like this; the Russian government during World War II decide to keep five POWs awake for fifteen days. Long story short, they go insane. When the KGB check on them at the end of the fifteen days, they have killed one of the prisoners, self-harmed, torn out their own organs, are lying in a mixture of blood and water, want to stay awake at all costs, are consuming enough oxygen for strenuous exercise, and eaten their own flesh. It turns out they have transcended insanity: they have become completely different people, and believe that if they go to sleep, the sane people will come back and they will die. This theory isn't completely unfounded, either: the moment two of them go to sleep, their hearts stop. The story ends when a commander suggests that they go back on the gas (along with some researchers), so one of the researchers kills him and the subjects, with the last survivor giving a creepy monologue about how they are the basic form of humanity. Nightmare Retardant is available: although the person who wrote it was obviously very good at horror, the grammar and spelling slip sometimes, and s/he apparently can't count, adding in an extra subject. Also, the EEG monitor wasn't invented during WWII, and the ending monologue is both implausible and quoted from The Twilight Zone.
The Keyhole. It's about a guy who stays at a hotel for the night, but is warned to avoid a specific room because of a murder that occurred there. However, his curiosity gets the best of him, and he peeks through the room's keyhole to find a woman with completely white skin leaning against a doorframe, but looking away from him. He looks through the keyhole again the next day, but this time all he can see is nothing but red. When he asks the receptionist about the room, he's told that the people who were killed in the room were strange, with white skin and completely red eyes.
Seriously one of the most depressingly messed up stories of all time.
Despite the obvious lack of technology knowledge, this is admittedly a story that's scary because it allows your mind to fill in the blanks, which was probably the point. Imagine watching the episode as you read. Remember how creepy Skinny Cartman looked when he was crucified in that one South Park episode? Enough said.
Blueberries. The narrator is convicted of a crime he (so he says) didn't commit, and is not allowed to leave his cell until he eats an entire oak desk. His sledgehammer is taken away after his initial round of smashing, and most of the pieces left over are too big to swallow. And then he sees that the top of the desk only broke in half.
And then, often lumped in with the many other Lavender Town-based creepypastas, is Pokemon Black (not the actual game, but the creepypasta born in the pre-DS era about a hacked Pokemon Red cartridge). What's especially unnerving about Pokemon Black is that... it's not haunted. There's nothing supernatural at all about this story. While it would take a very skilled hacker to pull it off, it does legitimately sound like it could possibly be a real hack... and the fact that it could exist is enough to send shivers down your spine.
The creepiest thing about some of them, like Dead Bart and Squidward's Suicide, is that the actual episodes mentioned sound like somebody actually had a nightmare about The Simpsons and Spongebob Squarepants, and are now just telling you what happened in it.
The creepiest thing about Russian Sleep Experiment is the fact that it shows you what could happen if you were deprived of sleep. What side effects are there of reading too much creepypasta? Yeah. Sweet dreams.
Probably the creepiest thing in Happy Appy is when an episode of the titular show depicts the events of 9/11 two years before the attacks take place. Then when part of the plane lands on and pins a child to the ground, Happy and the other children stand over him as he's screaming in pain. The other children ask Happy (who's thing is healing children but actually killing them just because by the way) if they can help the boy, Happy just coldly states "That's natural, children." and leaves the boy to die.
While Jeff the Killer isn't particularly scary himself, his face makes for an excellent shock image that is very hard to get out of your head.
For those of you to scared to look up the image, imagine Michael Jackson and The Joker mixed into one single abomination.
His origin story: Getting disfigured and then killing his family, later starting a killing spree.
Though for some, Jeff the Killer's origin story is unintentionally hilarious Nightmare Retardant.
If you live in a rural area, this one  could give you nightmares. especially given that its a story about The Rake.
Most of the written Creepypastas are bad enough when read, but having somebody ELSE read them? Look no further than the aptly named "Mr. Creepy Pasta". The narrator normally doesn't sound bad - in fact, he sounds like a normal guy, occasionally stuttering and slipping up on his words. But when you remember most of the Creepypastas he reads are about ordinary guys, often after they've hit a Despair Event Horizon, or Heroic BSOD, or are otherwise beginning to Freak Out from the assorted horrors they're put through, his voice nearly acts as an Audience Surrogate for the reactions the viewer would have in the narrator's position. Throw in some creepy music and Stock Sound Effects (some doubling as Scare Chords, like screams, gunshots, etc.), and Mr. Creepy Pasta is able to jack the horror of nearly any Creepypasta even further than one could conceive. Oh, and by the way, his library of narrations is EXTENSIVE at this point, and includes most of the aforementioned stories, other good ones not mentioned, some that were actually cliche-ridden and semi-Narmy until he... "fixed" them... and even has collections of "original" Creepypasta. All in all, if one's SOMEHOW getting jaded from Creepypasta... Mr. Creepy Pasta will make all those stories scary again...
The Gündschau Effect, a story about a Nazi experiment with Polish prisoners to test the effects on people's moralities if they're fed very good food, but are otherwise in hell.
This was done in real life, only not by the Nazis. Solzhenitsyn and others who were guests of the Gulag recount how this was standard practice at the Moscow Lubyanka, the prison/interrogation centre that was the first point of call for those accused of anti-Soviet benaviour. Prisoners were starved, tortured, deprived of sleep, had their sleep freqiently disturbed by noises and bright lights... but were fed the best possible food prepared by gourmet chefs. This mind-fucked many into signing confessions so as to go on to places where their treatment would at least be consistently nasty so they knew where they stood. Alexander Solzhenitsyn recalled a variant on this: prisoners would be treated with care and basic human decency (with a hint of worse to come). However, their meals were faithfully home-cooked to a standard they'd expect at home. There would just be less than a child-sized portion on the plate, to both keep them hungry and to act as an agonisingly tantalising reminder of the normality they had been dragged away from. this too coould drive a prisoner to confess out of sheer homesickness and cumulative undernutrition.
"Liars". Jeez it's the more horrifying and more depressing version of "Jeff the Killer". The description of the videotape is by far the worst part.
The writer describes the corrosion of the protagonist's skin with acid like it actually happened to him, making it even more disturbing.
And while the smile description at the very end is disturbing, look t the main image and imagine THAT being the last thing you see before you die.
Would you believe that Axis Powers Hetalia isn't safe from this? Axis Powers Hetalia: Episode 23.5 is an apparent "Lost Episode" of Hetalia that takes place while the Axis are camping on the beach. They run out of food, end up having to make a very rash decision and...well, let's just say poor Italy gets the short end of the stick. Did we mention that there are pictures and they very closely resemble the real Hetalia?
This reading of "The .GIF" which turns into a god-damnscreamer.
Made me sleep with the lights on, that one.
Funnymouth is not particularly scary in itself, but the author made it seem very real. He took the name of a forum-goer with several quotes on Bash.org, he set up the website mentioned in the story, exactly as it was described in the story, and if not for the dream invasions, the villain could have just been a really good Troll.
Psychosis, about a man who slowly comes to believe that everyone but him has disappeared and been replaced by some Eldritch Abomination, is an extremely scary story likely to induce serious Paranoia Fuel in you. Particularly effective is the Wham Line at the end.
"After all, a sane man would have fallen for the deception long ago.
"Self Preservation" Imagine a zombie apocalypse, except the zombies are very much the people they once were, crying and apologizing as they devour their neighbors alive, actively trying to prolong their demise just to keep themselves from dying a no less horrible death. It's difficult to tell who you should feel sorry for.
Abandoned By Disney. A curious blogger sneaks into an Expy of the Discovery Island Disney resort, whose very existence Disney has attempted to censor after inexplicably abandoning it. At first it appears to be just an impressive case of urban decay but then the author started noticing things are "off", with meat hooks in the kitchen swinging for no reason, the water still running despite everything else crumbling, hearing whispers, and dangerous animals from the resort still living in the ruins. And after encountering some of the Resort's released wildlife he finds the Mascot Dressing Rooms.... and discovers there was a damn good reason why Disney pulled out and wants no-one getting into the resort... or anything getting out.
The same author later released a parody prequel of this story in the form of an employee suggestion box for the resort while it was still active. While played for laughs initially, it still gets extremely sinister once fridge horror sets in as it describes the first supernatural events in the resort, the resulting insanity among the staff, and finally the employees becoming trapped in the possessed mascot suits, even as their bodies rot and die and the remaining staff locking everyone inside the park as the demonic "negative Mickey" from the original story emerges.
And now there is a fully fledged sequel by the same author "Room Zero" in which the same blogger has to deal with being stalked by some unknown party which is extremely irritated at his publicising the truth about Discovery Island (and anyone else who reposts his story) all while he delves into a series of even more sinister events at Disneyworld as told by some anonymous employees, including the "Gascot" sightings of unknown people wearing disturbing Disney themed Gas Masks◊, the eldritch events at a waterslide, the sinister "corpse disposal" procedure for Mascots who suddenly die, and the seedy underbelly of Disney's exclusive clubs. All of which subtly or directly revolve around an unspeakably nightmarish incident in the 1960s which seems to be the cause of all the demonic events at the Disney resorts.
Furthermore the sequel provides several gallons of Fridge Horror when considering the aforementioned "parody" prequel given how its heavily implied that the "Gascots" succumbed to the same demonic possession as the Discovery Island Mascots, which coupled with the "dead mascot disposal" instructions suggests that anyone who wears a Disney mask or costume is in danger of being possessed.
Never fear, Disney cast member here with some Nightmare Retardant: The Mascot Dressing Rooms are " behind a door labelled "Employees Only"- this is not Disney's practice. At Disney, all Employees are called "Cast Members," so you would never find a door on Disney property marked for "Employees" only."
" The truck was full of children. Some in pajamas, others dressed for school or church, some naked and others wearing heavy clothing that was all wrong for that time of year. Some were moving, others appeared to be long dead and decaying, bone showing through greenish skin. They were packed in there. Not standing shoulder to shoulder or sitting in a cluster, but PACKED. On top of each other. Floor to ceiling."
And after escaping, his reaction to realizing he had to go to Stonebridge, not Bridgestone:
"The Cemetery" puts a twist on the original urban legend "Grave Digger". Let just say, Pa had a good reason for asking those questions.
Almost every single short story credited to Slimebeast. Not only responsible for the creation of "Abandoned by Disney" and "Extra Ketchup" above, but a whole slew of the most inexplicably terrifying Creepypastas can be attributed to him here
"Nightlight" is more unsettling than outright scary, but it still applies here since it's never been certain whether the creature in the narrator's dreams really was a figment of his imagination or a real entity.
"On A Hill" Part 1 and Part 2. It shows a darker portrayal of the Scottish highlands by the form of a lonely hill in a small, unassuming village whose very presence fills the locals with all-consuming fear and trepidation. And for good reason too, because the abandoned church at the very crown of the cursed mass is not completely abandoned, as our unfortunate protagonist finds out when he ventures there by his lonesome.
"Kagome Kagome". What the Nazi scientists did to those children as part of their immortality research. Even worse in that while the disclaimer below admits the creepypasta is fabricated, he points out that the Nazis nonetheless did send a research team to Japan to experiment with immortality. And it was done on children. In an orphanage.
Now in song form, Seriously i had no idea there was a creepy pasta that mentions the same topic.
Most creepypastas on the Crappypasta site. Mind-bendingly awful but in a completely different flavor. Although some have had the ignominy to reach memetic status.
Dimelotu from DeviantART decided to take the most widely known Creepypastas and bring them to life in eye-popping 3d
The Smiling Man: Not too long or difficult to read but boy is it unsettling, even if it is full of Narm Charm. What's worse is that someone apparently had the same sentiments and made a short film version on youtube called "2AM".
Rap Rat and Mr. Mix: Warning! Clicking on this link will put you face to face (geddit) with two of the most hideous faces straight from the black hole of the Uncanny Valley. Like many others popping up these days, each is about an old VHS game inhabited by an indescribable evil. However, both still manage to be terrifying because they come from ordinary 1990s video games specifically catering towards little children.
The Never Ending Road: More mundane that most entries on this list, but the possibility of accidentally plunging off a cliff straight towards an untimely death is a real fear for many drivers who live near steep areas.
Skinwalker: No matter what you do or where you go, the Rake will always find you. And he isn't just going to watch you sleep.
The Camera Man: It looks like the Rake has a close relative. And he doesn't like to be seen either. Especially on camera.
"It's kind of hard not to get used to it when it starts coming from your closet."
Arizona: Hope you don't find any abandoned gas stations in Arizona....
NoEnd House is a pretty creepy read as well, where the main character is forced to go through nine different rooms of a house, that after the first couple, get more and more surreal and play on phobias and Primal Fears. The only solace is that the ending is a bit of Black Comedy, where the main character gets the $500, as promised...that is until the end of this last line.
Unbranded Laptop is pure nightmare fuel in every sentence, with Infant Immortality taking its first cut on the right cheek. What's worse is the final sentence, where the person watching the laptop will likely experience the same fate.
The Screamer's Forest: Those guys should have just spun a bottle in their house rather than spending the night in a land cursed by Native Americans.
Thumbs Out: Whatever that....thing on the road was, it certainly was patient enough to walk 30 miles towards the destination of the couple that failed to pick it up when it was hitchhiking two days ago.
If reading this page has caused Nightmare Fuel, there is Nightmare Retardant in the form of Trollpasta. The best known ones are AND THEN A SKELETON POPPED OUT, WHO WAS PHONE?, and TEH DAY OF ALL TEH BLOD.