This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / A Nightmare on Elm Street (1984)
The most famous two deaths are Tina's death in which she's brutally dragged across the ceiling of her bedroom and when Glen is pulled into his bed and turned into a geyser of blood.
"I'm your boyfriend now, Nancy."
Any scene involving the dream version of Tina's body, highlight being that giant centipede coming out of her mouth.
Rod's blankets slowly wrapping around his neck, before eventually dragging him up so that he can be hanged in his prison cell.
As tacky as the scene was, at the end when the car hosting the colors of Freddy's sweater whisks away the shocked kids in it while the happy mother waves goodbye before she is sniped through the window while children are singing the eerie song... That scene just...why.
The special effects failure amplify the, er, nightmarish surreality of the final sequence.