What makes that especially freaky is not so much the revelation that Jack's gone insane, but the implication of how long he's been going insane.
Who wouldn't be terrified by that scene where Jack Nicholson goes absolutely insane?
The point where Wendy, finally able to see the ghosts, runs into Grady with his skull visibly split. "Great party, isn't it?"
This lovely moment. Wendy, half-insane after her husband trying to kill her and all the other crazy shit she's seen that night, stumbles upon a dude in a bear suit blowing a well-dressed middle-aged man. And that horribly spooky music just sends chills of me spine. If you walked in on that couple in real life, living or ghosts, and they gave you that look, like you were the depraved one, chances are you would run the fuck outta there. Not to mention, in the book the man in the dog/bear suit is wearing said suit and performing the favor because the man in the tuxedo manipulated and broke him through psychological abuse.
The encounter with the woman in Room 237 who turns out to be dead and decaying... after Jack lustily embraces her.
You think 237 was bad?, you should see the woman in Room 217 from the 1997 Shining mini-series. You're not quite the same afterwards...
Hell, the basic premise that someone you love and trust could go batshit insane and try to kill you is damned freaky enough on its own without all the ghostly trappings...
Imagine you have a parent who's been struggling with addiction and anger issues. They love you and you love them, and they really have been trying to beat their problems for themselves and for you. Then something happens and they snap right back to how they used to be. They frighten you, you're not safe around them, and you can't trust them not to hurt you. And there's no solution to the problem anymore. Even without the supernatural trigger, it's a disturbingly realistic situation.
"Come play with us, Danny. Forever. And ever. And ever." (That you can't quite see what their dead bodies look like makes it worse.)
Jack Torrance later says it in the same manner.
The girls and Jack Torrance say "Forever. And ever. And ever." is the same manner as Alex from A Clockwork Orange before he makes his suicide attempt.
Shelley Duvall in and of herself is pretty freaking scary. Shelley Duvall contorting her face in terror? Almost unbearable. Probably because Duvall was probably not acting. Kubrick worked on making her as unnerved and on-edge as possible while filming the movie.
Dick spends the entire movie traveling across the country to investigate a hunch. He gets an axe in the chest as soon as he walks in the door. Try watching this movie as a ten-year-old...
Even worse, Stanley Kubrick, being an obsessed perfectionist, had Nicholson & Crothers shoot the scene 42 times. Crothers eventually broke down, sobbing his eyes out, and screamed at Kubrick, "WHAT DO YOU WANT FROM ME?!?!"
The music, especially the opening theme. You know you have one hell of a scary ride ahead when just the opening theme makes you want to watch this with the lights on.
Hector Berlioz' "Dies Irae" from "Symphonie Fantastique", electronicized by Wendy Carlos.
The native American chanting and/or screaming in certain scenes (like when Wendy runs up the stairs just before stumbling upon Dogsuit Man and Derwent), and the weird ululating noises in the opening scene.
Utrenja, which seems to exist solely to make people scream. It always comes suddenly, ear-splittingly loud, and the rhythmic knocking sound is like a pair of skulls being smashed together. Shows up when Jack axes Halloran, when Wendy sees the REDRUM sign in the mirror, and several times around the climax.
Hell, Krzysztof Penderecki's contributions to the score as a whole, which rely on Drone of Dread and Scare Chord to be scary.
The novel was scary in its own right, especially those moving topiary animals and Jack being haunted by his father.
And, of course, at the end of it all, when all of a sudden, the face of Jack completely frozen with a terrifying grim face, eyes completely open and dead, and teeth out. The music makes it all worse, as its one hell of a Scare Chord coming from out of nowhere, along the image. Just when you thought it all ended, the movie just won't let you go without a final scare.
What's even worse is that his expression is almost identical to the one he wears in the US version after he takes his first drink at the bar — the one he offered his soul for.
In 2013, King published Doctor Sleep, a sequel to The Shining that focuses on Danny as an adult. A synopsis is available on one of the wiki sites here. Please read at your own risk.
The scene where an almost-completely deranged Jack Torrance tries and comfort Danny...while this music plays.
And he tells Danny "I want to stay here forever...and ever...and ever." Yipe.
Jack confronting Wendy after the reveal of his sanity slippage with the infamous (Above example) "All work and no play makes Jack a dull boy". The whole scene is Nightmare Fuel in its own right. Jack has become a ranting, insane shell of his former self. Wendy is traumatized, frightened, confused and scared for him and their son's well being. As she pleads to him Jack continues mocking her and backing her up the stairway before Wendy successfully knocks him unconscious with her baseball bat and drags him into the dry goods food locker.
In the same scene "I'm not gonna hurt you." [beat] "Darling, light of my life, I'm not going to hurt you. You didn't let me finish my sentence. I said 'I'm not going to hurt you... I'm just going to bash your brains in!' I'm going to bash them right the fuck in." and then the look and faces he starts making after that little speech... shudder*
The final shot where the camera zooms in on a picture of a party from the 1920s, where Jack is seen between the guests, as if he always was a ghost in the hotel. Add some more creepyness to the fact that, at that moment, the hotel is back as disturbingly empty as it was before...
Lloyd the bartender. Joe Turkel's performance is so creepy. All he does is stare unblinkingly at Jack, smile politely at him and give him a drink, and yet he still manages to come across as evil incarnate. Maybe it's the Nothing Is Scarier effect that he never does anything scary like the other ghosts, but you know he could if he wanted to.
Jack's behaviour when he comes back from Room 237. There's none of the palpable resentment below the surface of all his interactions with his family up to now, no creeping influence of the hotel driving crazy, or even the vaguely "wrong" quality he gives off in the interview scene — it's so mannered, so uncharacteristically gentle, so obviously artificial, as if something were trying its hardest to imitate a good, reassuring husband and keep Wendy and Danny feeling nice and safe with him ... And then the sheer rage that starts pouring out as soon as Wendy insists they leave the hotel, with the sense that every bit of it is coming purely from Jack.
Tony in the film. In the book, he's Danny from the future, but the movie never divulges who or what he is. We're left with nothing but his insistence that he doesn't want Danny to talk about his Shining, Danny's tenacious avoidance in describing Tony in great detail, and the ominous and vague mentions that Tony tells Danny to "do things."
The blood flooding out of the elevator. Its an iconic shot from the movie, yet its completely illusional, a symbolic vision of the horrors hiding in the hotel. Only Danny can see it, and presumably Dick Halloran as well.
The woman from Room 217 from the book, atleast the woman in the movie starts out looking attractive. Not so here, even when she was alive she was pretty ugly. When Danny finally runs into that partiuclar haunting, he tries to do what Dick told him and ignore her, so her ghost wont be able to touch him It doesnt work..
Even worse, she is one of the ghosts that followed Danny home after the events of the novel, and reappear in Doctor Sleep. Danny seals her inside his mind.
King once talked about his inspiration for the novel, he and his wife were out on a trip, and stopped at a hotel that were just closing up for the winter, and manned with a skeleton crew, leaving them almost completely alone in the building. Imagine having to stay in a place like that.
Doctor Sleep fleshes out some of the backstory and setting of the Overlook Hotel, its revealed that the sheer amount of ghosts at the place is because the area is saturated in supernatural energy, allowing ghosts to manifest easier than they otherwise would. They also reveal that the only ghosts who linger in the mortal world are usually the ones who know that something much worse awaits them on the other side for their crimes.