This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Young Justice: Darkness Falls
Artemis goes ballistic on Nightwing for hiding the possibility that they'd be able to track Wally. So much that she actually does a Rage Quit, choosing to ask for help from her sister Cheshire rather than have the Team help her out. Both of them have points, but seeing Nightwing called out for his secrets AGAIN is not easy to watch.
Victor Stone finally wakes up, only to know for certain that he'd been orphaned and made a Cyborg.
Artemis's grief over losing Wally hangs over the fic in many ways. It was not easy for her to move on.
She left the house they shared and moved back to Gotham with her mother because she couldn't stand the thought of him once being there.
And then we find out that after Artemis got picked up from the summit, Wally Proposed to her. That's right. They were going to be married, and then he "died" saving the world.