This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Kuroko no Basuke
Seirin's loss to Touou in their first game. Despite giving their all, the game ends with their score doubled. You may have seen it coming, yet it still hurts to see them defeated after making it so far. It makes it all the more satisfying when they win against Touou during their rematch.
Kuroko crying after being told he isn't fit for the basketball team, despite him even taking extra practice in hopes of improving himself. Anyone who worked hard for something yet was told that they aren't cut out for it would relate.
The entire Teiko Arc can be seen as one for everyone involved.
The numbers 111-11 will become incredibly disheartening once you see the chapter featuring said numbers... or scores, for that matter. At this point, everyone already knows that the Generation of Miracles has become extremely arrogant and dispassionate about basketball, yet no one would ever think that they would stoop so low.
Watching the Kirisaki-Seirin match becomes straight-up painful as the team clobbers lovable, already-injured, teddybear Teppei to within an inch of his life. They lose, but it still hurts.
When Ogiwara cheers Kuroko on in the final match, Kuroko sheds happy tears. It's tearjerking when you remember that all this time, Kuroko blamed himself for what his former teammates did to Ogiwara; and this scene shows that Ogiwara still believes in Kuroko and doesn't hold it against him at all. It also counts as a Crowning Moment of Heartwarming.