This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Shutter Island
The woman patient whom Teddy and Chuck interview, who chopped up her husband with an axe after finding out he was cheating on her. Teddy notes that she speaks more rationally than the other patients, but she expresses that she doesn't want to leave Shutter Island because the world has changed so much and she'd be a Strangerin A Familiar Land.
Any of the scenes of Teddy with his wife, in particular the ending.
"Why are you all wet, baby...?"
Teddy taking the shoes off his daughter's body, trying to rub her feet warm.
"Your children, Andrew, your children! Simon! Henry! Your wife drowned them at the cabin by the lake. And here, the little girl. The one you dream of every night. The one who tells you over and over that you should have saved her, saved them all! Your daughter! Her name was Rachel! Are you going to deny that she ever lived, Andrew? Are you?"
The strong possibility that in the end, Teddy willingly allows himself to be lobotomized rather than live with the memories. He'd rather "die as a good man" than "live as a monster".