"Candy Hearts and Paper Flowers" from the animated Raggeddy Ann & Andy Movie is my special daddy song when I'm getting my son into PJs or trying to cheer him up if he's sad. I never cried at it, always thought it was sweet. Then when I came completely unglued in the fall and started envisioning / hallucinating his death and funeral, part of the imaginary ceremony was the whole family singing that to the little coffin before we buried him.
Even after I "got better" the song was kind of ruined for me. I still sing it to him but either with the lights out or positioned so if I tear up he won't see.
The "upside" is that if I ever need to self-trigger or whatever, to let more poison out, I sure know how.
Oh, and also the part in the Neverending Story where the kid has a slow horrible desperate meltdown as he helplessly watches his horse slowly drown. Niagara Falls. (There's another scene later in that movie that doesn't make me cry but rather honestly scares the shit out of me ever since the CSA woke up. To be precise it terrified me my whole life but only now do I understand why.)
"Don't think it hasn't been a little slice of heaven just because it hasn't!" --Bugs Bunny