This is based on opinion. Please don't list it on a work's trope example list.
Nightmare Fuel / Halloween II (2009)
The absolute out-of-nowhere scene where Laurie has a seizure. Bound to throw you off if you're watching for the first time.
Laurie during the ending. That dead look in her eyes...the creepy smile...seeing the same vision as Michael....
Who won't mention the nurse scene?! For those curious, The infamous scene starts with Laurie walking out of her room to seek help. After a nurse leaves a room, Laurie asks her she needs some medication for her head. The nurse slowly turns around to reveal bleeding from her chest and then letting out an agonizing scream. Oh and Michael proceeds mutilate her.