This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Batman: The Dark Knight Returns
While watching Wayne Manor explode and burn, Alfred has a fatal stroke.
A jolt travels the length of Alfred's spine. "Of course", he thinks as his head goes light. "How utterly proper."
And let's not forget the Cub Scouts at the county fair. God...
One of the few times Bruce doesn't respond with anger or stoiciness but looks genuinely sad.
And Superman begging for his life after being nuked and blocked from the sun.
Poor Gordon sees a woman fall from his burning apartment building, and for a fleeting moment he thinks it's his wife Sarah. It's not. Jim barely gets his Heroic Resolve after seeing this, firmly denying it's her, but doesn't reunite with Sarah for a couple of pages.
The fact that Batman and Superman are to fight each other. Despite the epicness it is to see them fight, it's just as much of a Tear Jerker when its clear that neither of them wanted this to happen. When this first came out this was a very emotional scene to the readers as well.
Bruce's funeral. To those who did not realize he was faking it.
"At least both sides match now, right? Look at me! And have your laugh..." Poor Harvey...