These are so good that reading them needs to be on your bucket list)
Has Anyone Heard of the Left/Right Game? - This one and Infected Town are tied for being my favourite creepypastas ever. A journalist meets a eccentric old man who has become obsessed with a ritual game that he found online. A game which involves driving around in a car and taking the first possible left turn one runs into, then the first possible right turn, and so on, until the player winds up "somewhere... new."
If I had to sum this story up in one word, that word would undoubtedly be "atmospheric." If I had more words, I would also add "scary" and "melancholic." The writer does an incredible job at truly selling the idea of the cast having entered some unknowable realm outside of reality, and it's always entertaining to see the various ways that the cast members react to the increasingly dire and unexplainable situations they find themselves in. This is one of the longest creepypastas out there but the quality is more than worth the time it takes to read it.
Infected Town (AKA The Mold Series) - An incredible creepypasta series about a town that is steadily being taken over by an eldritch mold infestation. The story starts off rather slow but gets steadily more and more horrifying as it goes on. The story is very immersive, with the author including photographs that she took in the infected town and telling the story from the perspectives of multiple characters writing from multiple reddit accounts. It's one of the longest creepypastas around but much like with the Left/Right Game, this is a good thing. The story never gets boring or slow, and the thrilling climax would be worth it even if it did.
The Patient That Nearly Drove Me out of Medicine - A series detailing a new psychiatrist's attempts to reach a troubled, inscrutable patient who has been locked away in a mental hospital for the majority of his life. The story takes many horrifying twists and turns and the horror never lets up for a moment. The characterisation and the descriptions in this story are an absolute treat to read and truly make you feel like you're right there with the overwhelmed psychiatrist protagonist.
Psychosis - The first creepypasta on this list that isn't a series, Psychosis is a first-person narrative tale of an isolated young man having an increasingly intense psychotic breakdown. I won't spoil anything but the tension and horror only grows as the story goes on, and it has one of the most memorable endings of any creepypasta ever.
Penpal - A classic nightmarish tale of woe about someone reminiscing about strange events that happened to them when they were a kid, and realising that their idyllic childhood was haunted by something very dark that their young mind could not comprehend at the time.
Something Happened 63 Years Ago That's Haunted Me My Entire Life - An old man tells the tale of a horrifying paranormal experience he had as a child that has continued to haunt him for the rest of his life. Although I am hesitant to put anything that isn't a series into God Tier, I will make an exception for this one. The writing is excellent and the story is genuinely spine-chilling.
These are wonderful but not on the level of the literary masterpieces in the previous tier.
I'm a Search and Rescue Officer for the U.S. Forest Service - A classic series about a forest Search and Rescue officer recounting their many strange and paranormal experiences deep inside American national parks. The author does an excellent job with balancing the paranormal bits (mysterious, magical staircases deep in the woods) with completely believable events to make the story seem completely plausible. One might say that she did it a little too well, considering parts of the story wound up becoming popular outside of the creepypasta community after some people thought that they really happened.
Candle Cove - A pretty short, classic creepypasta written in the form of an online forum discussion about an odd show that aired on a local TV station decades ago. Surprisingly scary despite the brevity and the subject matter.
The Story of Her Holding an Orange - I love this story and I really want to put it into the god tier category but... I just can't. The premise of the story is excellent and it's one of the scariest creepypastas out there overall, but the writing quality is abysmal far too often. I realise that this is intentional because the protagonist is meant to be a non-native English speaker and a young male, but even that doesn't excuse the comical overuse of foul language that pervades the entire story. The ending is also extremely abrupt and lazy.
This story was later released as a book, which massively improved on the story, fixed the writing problems, and included a fleshed out ending that actually brought proper closure to the story. Unfortunately, this is a list of creepypastas and not books, so I am grading this entirely based on the original story.
Third Parent - A nightmarish, NSFL tale of a malevolent entity that invades people's families and spends half a decade tormenting them in increasingly horrific ways under the guise of helping them become better people. The author wrote severaladditionalstories in the series, as well as a book that provides both an origin to the third parent, as well as a permanent end to it. If you're squeamish, be warned that this probably the most gruesome creepypasta out there.
Fuck Oranges - Another horror story about oranges, this time from the creepypasta legend M59Gar (of Psychosis fame.) While this story could honestly be better classified as comedy rather than horror (or horror-comedy perhaps,) it's quite entertaining and easy to read, so I'm putting it here.
I Met Someone Who Claimed to Be the Devil - A very well-written account of one man's encounter with the Devil at a bar. Between the terrifying existential dread, interesting religious lore, and surprisingly likeable Light-Bringer, this story is a true gem.
Mr. Smiley - Don't be fooled by the silly name and how generic the premise of the story may seem at first, this is a very well-written horror story with one of the most shocking plot twists that I have encountered in a creepypasta.
1999 - A classic pasta about a local children's TV channel operated by a mysterious kidnapper and murderer known only as "Mr. Bear."
My Grandfather's Final Invention - An eccentric old man who enjoys doting on his grandchildren by inventing odd gadgets for them accidentally goes too far with his final attempt. The twist at the end is wonderful.
The Girl the Universe Forgot - An equally melancholic and existentially terrifying tale exploring just what the "Mandela Effect" might lead to, if it does indeed exist.
Doors - Another classic pasta, and one that truly deserves that title in every way. It's short, sweet, and exquisitely macabre.
The Devil Game - One of the exceedingly few genuinely excellent ritual pastas out there. This one details a ritual that supposedly allows one to speak with the Devil himself, as well as the many macabre potential pitfalls that it can lead to.
Wendigo - A man recounts his deceased uncle's tale of his encounter with the legendary Wendigo monster of Native American lore. The rural 1940s Canada setting is very convincingly portrayed, and it's very easy to feel like you're right there with the characters.
A Cold Love Story - A schoolboy is stalked by an psychotic, and possibly demonic, girl from his school. Although a well written story overall, some of the dialogue is rather strangely, namely the stalker speaking like a clingy anime girl. This somehow serves to make the story even creepier so it all works out.
These are just average. Not spectacular but not bad either.
The Russian Sleep Experiment - An oldie that seems to owe most of its fame to its age, as opposed to its quality. This one tells the story of a group of what happened to a group of Russian prisoners that were drugged and forced to stay awake for 15 days straight. The over the top horror gets dulled a bit by the fact that similiar sleep deprivation times have been achieved in the real world without anything unexplainable occurring.
NoEnd House - Another famous oldie, although unlike the previous one, this is one of the better stories in this tier. A man makes his way through a haunted house that promises a hefty cash reward in exchange for doing so, only to find out that the building is far more extreme and dangerous than any haunted house.
Spiderland - I feel like I'm being a tad nice by not putting this under Trash Tier, but it did entertain me despite (or possibly because of) how little sense it made. This is less of a creepypasta and more of a "confusionpasta."
Tales From an Ex-Convict - This one is actually an incredible read, although it loses major for points for being unfinished and ending at a fairly dramatic cliffhanger. A man writes about his ex-convict father's experiences in a prison that was haunted by the presence and increasingly horrific acts of a convict who is possessed by a powerful demon. The father-son duo then wind up teaming up to try to stop said demon after learning that it has escaped and gone body-surfing. I really hope the author finishes this one day.
Mr. Widemouth - Another tale of a boy being haunted by a malevolent entity, one that is not nearly threatening or original enough to differentiate itself from the pack. Thankfully, the story is just short enough to not be dragged down by this.
Lapse - A short and sweet tale about the horrific impacts of drug abuse. I really wanted to rate this higher but, while the premise is excellent, the actual story is written very awkwardly at parts and the twist is too easy to predict as a result.
The Fairies - A woman and her cryptozoologist boyfriend investigate legends of malevolent fairies living in the forests around her deceased grandmother's house. If fairies seem an odd choice for a horror story to you, this tale will most likely change your mind.
Dogscape - An equally bizarre and gruesome tale about the Earth being taken over by an eldritch mass consisting entirely of canine body parts. Not recommended for anyone who is at all squeamish.
These are creepypastas that are meant more to make you cry than to scare you.
Safe - A sorrowful tale of just how far the power of a mother's love for her child can reach.
Dandelions - A sad (and creepy) love story that is guaranteed to make you cry. 'Nuff said because I don't want to spoil anything.
Maria on the Moon - An exquisitely morose tale of love and loss. Losing the person you love the most is already horrifying without being beseiged by eldritch beings at the same time.
All Eighteen Lives of Omen the Cat - I put this in the feelspasta category but this could also easily be classified as a regular creepypasta. This is an equally heart-warming and creepy tale of a two-headed demon cat and their loving family.
Note: I am including these stories in their own category not because I think they're bad, but because a lot of people don't like feelspastas. Personally I think the ones on these list are some of the best creepypastas out there, but different strokes for different folks (nmiaow) and all that.
Self-explanatory -- don't bother with these unless you feel like wasting your time on drivel.
Jeff the Killer - I have no idea why this story gets brought up so often in discussions of the best creepypastas. It's a "classic," in the sense that it's one of the early ones, but that's all that it has going for it. The writing is atrocious and the plot is incoherent at best.