You all should see what Main/folieadonteven did to THEIR OWN TV Tropes page...
Oktober starts out fairly normal, then you notice that they seemingly can't spell Oktober right, and every character's interpretation of Katie seems to be different, and then they start doing backwards text parables, and then Natasha gets body-snatched by someone called Echo, and Katie's trunk is revealed to be some sort of portal to an alternate reality, then there is the whole Labyrinth thing and by the end of Book 1 NOTHING MAKES SENSE.
Certain veins of lonelygirl15 videos veer toward this. Specifically, while LaRezisto consistently has a few clear points amongst the smoke and mirrors, OpAphid just seems to be weird-for-the-sake-of-weird half the time.
OpAphid is like that. It's even worse in Redearth88.
The League of Intergalactic Cosmic Champions had some moments: the idea that it was both a story of superheroes in the future & a TV show about superheroes in the future was one; the Queue's explanation of how they created the LICC universe was another; although the Gerber Elf was the only one we know was an intentional Mind Screw on the part of an author.
Sonic the Other Movie, an abridged series, suddenly and violently deviates from its source material in a Gainax Ending featuring background comic relief character Old Man Owl destroying the world after he is revealed to actually be a godlike entity pulling the strings of the entire plot. However, he allows the main cast to survive after Sonic's "World of Cardboard" Speech convinces him that these lower lifeforms he initially considered worthless maybe do hold value. He does however tell Sonic he's "made a powerful enemy" when he's weirded out by Owl's true name, Jezebel.
Nostalgia Critic: A cat and mouse are driving a ship trying to save the daughter of Indiana Jones while being chased by a purple people eater, a dog on a skateboard, a performing ship captain, his hand puppet Squawk, two Mexican wrestlers and a doctor riding an ice cream cart. Ladies and gentlemen, welcome to the Mindfuck.
And now we have Top 11 Nostalgic Mindfucks which will all no doubt be joining this article very soon... if they aren't here already. The Critic even gets in on the action by using several weird effects in the video and "numbering" the list from banana to theory of relativity.
He also suggests that Moonwalker should've been named 'Mind Fucker' instead.
And then there was the dream sequence halfway through the review for Junior. And for those of you who want to know about the music which plays during the dream sequence, the tune was "Phantoms" by American Space Rock band, Paik.
Everyman Hybrid: There's a lot of All There in the Manual information that implies that the characters are all part of a cycle of events that's repeated in the past. There are also videos on the YouTube channel that the characters can't see - and when they do find a way to watch them, very bad things happen. Eventually, Vinny works out that he's a fictional character, and that their various houses are actually just different parts of the same house.
But Revelation then manages to take it further by revealing that everything for the past 3 seasons was part of a Recursive Reality created by a previous iteration of Epsilon, which was in turn created by another Epsilon before it, etc.
That may be looking to much into it. At a minimum, there is only the original timeline, and a trapped Epsilon-Church reliving his memories to find Tex in the epilogue.
Word of God confirms this: Of the on-screen events, only the Blood Gulch sequences in season 9 occur within the Epsilon unit.
Sweet Cuppin' Cakes from the Strong Bad Email "crazy cartoon" is a deliberate example, as a viewer asked Strong Bad to make a "cuh-razy cartoon". It takes place in a mysterious void with Astral Checkerboard Decor, and the characters include a hovering, mumbling "cow-copter", a crudely-drawn talking wheelchair, and Strong Bad with a keyboard for a head.
The SBEmail "shapeshifter" has a series of Imagine Spots where Strong Bad imagines himself with the power to turn into any species of balloon animal, the power to turn into legal tender, and the power to turn into "almost" anyone in the world. Near the end, it's implied Strong Bad-turned-into-Bubs'-legs is in the same place as both Strong Bad-turned-into-a-hundred-dollar-bill and Strong Bad-turned-into-a-balloon-animal-tiger, even though those were supposedly separate scenes.
As mentioned on the fan works page, everything by Chriddof. Videos (over 300 of them) range from Youtube Poop-like vids to uncanny 3D animations to genuine-seeming videos with a twist to odd spoken words and downright surreal stuff.
Cyriak's videos, including this disturbing video starring a sheep. Baaa..
Deja Vu, a short film on YouTube actually has this trope as part of its subtitle, and for good reason.
Sonic the Hedgehog 2: Special Edition starts off normally enough, until random bits of footage start getting spliced in, and multiple levels turn out to be a Show Within a Show or All Just a Dream. Then the game starts breaking every fourth wall in sight, with Tails holding conversations with the player, and threatening the people watching the LP of the game. Then it spins the Gameplay Roulette wheel a few times, and pulls a few Fission Mailed scenes. By the time Sonic is flying through space, being attacked by Sega game systems, the player gives up understanding what's going on and just embraces the madness. Fittingly, the final boss is logic—which goes down with a single hit.
''Project Million" brings us Spazz trying to determine how The Wire got out of the television.
Spazz: How did you get here?
Wire: Get where?
Spazz: Like, here. In reality.
Wire: I'm not here.
Spazz: *poke* You are.
Wire: No I'm not.
Spazz: Well then what the hell am I doing, dreaming?
Wire: No, not this time.
Spazz: I thought that was an insane Inception reference?
Spazz: But isn't that also an Incep - how are you here?!
Wire: I crawled through a river of shit and came out the other side clean, okay?!
He spends the next few moments trying to figure out what that even meant.
APPLE.MOV, it starts out relatively normal with a few odd things in it up until Applejack eats too many apples.
How about the whole PONY.MOV series?
Mind My Gap. Have fun trying to figure out how the story's timeline works.
Candle Cove is a good, but fairly subtle, Creepypasta example. In short, a bunch of people who grew up in the late 60's and early 70's reminisce about a TV show that aired in 1971 on a message board. After establishing the show as being terribly not-for-children and one description of a nightmare about it, the last few posts reveal that the nightmare, which was just the characters standing around screaming and crying for 30 minutes, was an actual episode, and every time a kid would go watch Candle Cove, they'd just tune the TV to dead air and sit there for 30 minutes. So they all remember watching the same thing that never existed.
The SCP Foundation has SCP-1539, the Semantic Disassociation Zone (a basement which switches the identities of objects without changing any of their other properties). You'd think that regular readers of a website devoted the to weird and the bizarre wouldn't be fazed by anything, yet SCP-1539 manages to confound them.
Dr. Sanders: Can you tell us what you're doing? What is your name?
SCP-1782-1: It is a meat offering. Thou shalt put oil upon it, and lay incense thereon.
Dr. Sanders approaches the entity and the group of birds. They are non-hostile.
SCP-1782-1: Pour all the rest of the blood thereof at the foot of the altar, chickadees. In the hole in the floor.
SCP-1193 consists of a rather abnormally long arm of indeterminate origin and a telephone with a voice on the other end rambling on about surreal stuff like getting "stuck in the stove" and his(?) unusual bodily design.
The Cyphers from The Wanderer's Library, “is a collection of seemingly random quotes and musings, most of it handwritten. Based on the styles of handwriting found, the original authors number in the dozens. Some of these quotes have been deliberately arranged to form dialogues or storylike proses.” They make about as much sense as it sounds.
"A Bit Of A Pickle" is either the hallucinations of a schizophrenic or the tale of a sweet and innocent girl being driven to kill her friends by a sentient pickle. Or a sentient pickle killing people and framing an innocent girl. (Judging by a certain scene in "Royal Flush", they probably are being killed by a pickle and not Lammy, since that scene doesn't seem possible otherwise.)
"Double Whammy". If Good and Evil Flippy suddenly being two separate people despite the latter clearly being a split personality in every other installment doesn't confuse you, the moment when thousands of other Good and Evil Flippies suddenly appear out of nowhere will. Justified since they aren't really in separate bodies: it's all in Flippy's head. Towards the end of the episode, he realizes that he's been hallucinating the entire time. Whether this is the result of his general instability, the large number of pills he took towards the beginning of the episode, or both... is rather unclear.
Follow The Sun could best be described as "like Don't Hug Me I'm Scared, only creepier and weirder". The video starts out with a sign saying "For Enjoy", and ends with a bunch of popcorn boxes drowning in blood, several people who've fallen over, and a command to "EAT!".
While Welcome to Night Vale has its moments of mind screwing scattered about here and there, its crowning achievement of Mind Screw is episode 67 "[Best Of?]". The episode is framed as a substitute host doing a Clip Show of regular host Cecil's past highlights while Cecil himself is on vacation. To start with, every clip takes place on or near Lee Marvin's 30th birthday regardless of the actual year, some of Cecil's broadcasts predate radio itself, a Cosmic Retcon occurs mid-clip, the final clip is Cecil describing the death of his predecessor Leonard Burton, which is followed by the substitute host, Cecil's predecessor Leonard Burton, signing off. Finally, after the episode has finished and the credits and proverb have run their course, there's a lingering silence followed by the sound of a tape deck being opened. A sound which has wrapped up every previous clip up to that point.