Please don't list this on a work's page as a trope. Examples can go on the work's YMMV tab.
Tear Jerker: The Godfather
Vito torn by the news of Michael being the one who killed Sollozzo and McClusky.
Vito's reaction to seeing Sonny's body:
Vito: -weeping- Look how they massacred my boy...
From the very first scene:
Bonasera: They made her drink whiskey. And then they tried to take advantage of her. She resisted. She kept her honor. So they beat her, like an animal. When I went to the hospital, her nose was broken. Her jaw was shattered, held together by wire. She couldn't even weep because of the pain. But I wept. Why did I weep? She was the light of my life — beautiful girl. Now she will never be beautiful again.
Tom Hagen's reaction to Sonny's death. Particularly in the novel, where it's detailed that he feels as if he has failed.
Right after it's revealed Kay had an abortion so she wouldn't have to bring another child into the Corleone's ruthless world, the scene fades into a flashback of baby Fredo suffering from pneumonia, crying hysterically and Vito tearing up outside the door, feeling helpless. It's such a heartbreaking sequence, showing how much parents want to protect their children from experiencing pain and hardship.
Even before then, Michael slapping and shouting at Kay sounded more like he was scared than he was mad about losing his kids.
A one-two punch with Mary's death, followed by Michael Dying Alone
Not to mention the montage between the two tear jerkers featuring all the women Michael has lost - Appolonia, Mary, and, in a sense, Kay.
If one interprets the movie by the original title suggested by Coppola, The Death of Michael Corleone, then the entire movie is one big Tearjerker.
Speaking of Apollonia, Michael's flashback to their wedding day. When the flashback ends, he's in tears, showing that after all this time, he hasn't forgotten her.
Michael: I, uh, betrayed my wife. I betrayed myself. I've killed men, and I ordered men to be killed. No, it's useless. I killed... I ordered the death of my brother; he injured me. [He now begins to sob] I killed my mother's son. I killed my father's son.