This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / The Shining
Danny manages to bring out Jack for one last time.
The face in front of him changed. It was hard to say how; there was no melting or merging of the features. The body trembled slightly, and then the bloody hands opened like broken claws. The mallet fell from them and thumped to the rug. That was all. But suddenly his daddy was there, looking at him in mortal agony, and a sorrow so great that Danny's heart flamed within his chest. The mouth drew down in a quivering bow.
Jack's flashback in the beginning of the book to the time when he broke Danny's arm. The description of how it happened is gut-wrenching both in that a small boy is put through so much harm for something he was too young to know he was doing wrong (destroying Jack's manuscript and tearing up the papers on his desk), and because Jack didn't intend to hurt him that badly—he was trying to spank him but was clumsy from being drunk. He's so traumatized by how badly he felt both at hurting Danny and at Wendy's reaction that he still feels intense shame and guilt even thinking about it. Taken in context with what happens later just makes it worse.
Fridge Brilliance in that this is somewhat Truth in Television. Dislocations can be fairly common in small children, although it's more commonly elbows. (Hence the name, Nursemaid's Elbow.) It can be caused by something as innocent as swinging a child by the arms during play.
Wendy's telling of it in the 1980 film is equally heartbreaking. She's smiling to hide the pain, and while the way she tells it makes it sound like it was years ago, she finishes that in the last 5 months Jack hasn't had a drink. It was actually very recent.
Jack mentions to Lloyd the bartender that the arm breaking incident happened "three years ago."
There's a very sad scene late in the novel where poor Danny has a minor breakdown over having to face down the evil of the hotel essentially by himself, because his parents cant help him and Halloran is miles away.
Danny: I'm only five! Doesn't anyone care?! I'm only five!!
Not to mention a little while later, when Jack has been completely overtaken, and is trying to hunt down Danny, with Wendy and Halloran both too injured to do anything. The narration specifically mentions that Danny has "his very first adult thought", realizing that he has to survive this by himself.
Danny: Mommy and Daddy can't help me now...
When Halloran is almost overtaken by the remnants of the hotels spirit during the escape in the climax, he only snaps out of it because of Danny's desperate sobbing after him.
There's a few scenes in the novel where both Jack and Wendy despairs over how their own failures and shortcomings as parents, especially their trouble dealing with Danny's sombre personality and Wise Beyond Their Years intellect. This is especially poignant when they visit the pediatrician in Sidewinder.