Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: To Kill a Mockingbird
Jem feeling mighty awful that the hole that Boo has been leaving gifts and treats in has been plugged up by his brother. To Scout, it means the end of gifts while Jem as a bigger grasp on the cruelty toward Boo.
A good place to start would be "Stand up, Miss Jean Louise, your father's passing."
Another is "Hey, Boo." So much said in just two words.
And "Can you take me home?" from Boo to Scout. The idea that a grown man actually needs a little girl to take him from one house to the house next door because he can't go alone gets this troper every time.
Just think about him and start weeping.
The ending when Scout stands on the Radley porch and sees the events of the book from Boo's point of view always gets me teary eyed. There's just something so beautiful about that moment.
"In the name of God, do your duty."
Scout's final realization, when standing on the Radley porch and seeing the events as they unfolded through Boo's eyes.
"I don't know, but they did it. They've done it before and they did it tonight and they'll do it again and when they do - seems that only children weep."
The film: I know I cried when Scout talked to Mr. Cunningham in the lynch mob, when the black community stood up as Atticus left the court room even though he lost the case, and even harder when the reverend told Scout to "stand up, miss Jean Louise, your father's passin'", when Atticus receives the news that Tom Robinson has been killed and tries to convince himself the deputy sheriff didn't murder him, when Tom's father slouches into the house, moments after hearing his son is dead, being ordered around and called 'boy' by the man primarily responsible, and when Atticus, a man so fiercely protective of his children, trusts Boo Radley, a mute shut-in with a violent reputation, enough to leave him alone in a room with Scout and an unconscious Jem.
Atticus' speech about Mrs Dubose, that horrible, racist old woman, calling her the bravest person he'd ever known for having the courage to die free of her morphine addiction.