This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Good Wilt Hunting
The Reveal of Wilt's past. Wilt ran away from his kid Jordan when they lost a basketball game, which they only lost because Wilt moved to save his creator from getting hurt. He thought that Jordan could never forgive him, but it turns out that Wilt's leaving hurt him more than anything, especially once he found out how Wilt saved him and got injured in the process. Wilt spent thirty years believing that Jordan could never forgive him for letting him down, when Jordan spent all that time blaming himself for being so obsessed with winning that it led to his best friend getting injured and driving him away, and the flashback scene at their reunion is heart-wrenching.