Tear Jerker / Super Friends

• In the "Galactic Guardians" series, there's "The Fear". Egad, "The Fear". It's not the first animated rendition of Batman's backstory for anything. Especially when we see the flashbacks to pre-teen Bruce crying after his parents are killed off-screen, and then his first visit to Martha and Thomas Wayne's graves alongside the faithful Alfred.
  Batman: "And so, I found myself alone in the world. A boy who internally screamed for justice (...) From that day onwards, I vowed to avenge my parents' murder, by devoting my life to fighting crime..."
• "The Death of Superman" is a very powerful episode. The fact that Superman died, the other heroes (especially Firestorm) seriously mourn the loss of their friend, and the entire world deals with the lack of Superman all happened in a Super Friends episode is still quite the shock to first-time watchers.
• "The Krypton Syndrome", where Superman painfully realizes that if Krypton's destruction is prevented through time travel, then he would never have been sent to Earth, and the Legion of Doom will win.
  Superman: When Krypton was saved, my father never sent me to Earth. So, to this world, there never was a Superman.
• "One Small Step For Superman": A little boy and his dog get attacked by a bear, and the dog is actually killed. The boy is so depressed that he insists that he can't walk, even though he is perfectly healthy and uninjured. When the city is attacked by a robot, Superman tries to fight it, but it throws a chunk of kryptonite at him. With the boy the only one around, Superman pleads for help while the boy insists he can't do anything. Eventually, the boy finds the courage to get up and throw the kryptonite away, allowing Superman to defeat the robot.