This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Space Beasts
When Jim receives the fur coat that used to his mother. The moment is heartbreaking enough but when Jim confronts they guy who sent it to him you can just feel the heartbreak when the old human farmer tells Jim he did it just to rub it in Jim's face they're all orphans.
In the finale of the Phantom of Crystal Mountain story arc, Falco realizes there is nothing left for him and so decides to commit suicide. He sings a single high note that causes Crystal Mountain to fall on him. Ichabod, Marzipan, Bill, Jim and Bob can only watch as several massive boulders appear (Repeat APPEAR) to crush Falco, it later turns out that Falco survived (This does not go unlampshaded) Falco kisses his love the Dragon Girl Rose,and thanks to the magic Marzipan gave Falco, Rose is revived, Rose reveals that she wasn't dead just comatose, the magic woke her up, so Falco and Rose are reunited, Skeksis is dead, it would seem a happy ending, the only problem is the heroes don't know that! Marzipan and Ichabod assume Falco and Rose are both dead and it takes Marzipan a long time before she can find it in her heart to forgive Ichabod for snitching on Falco and Rose's affair (Which what caused Skeksis to poison Rose in the first place)
When Minsk's older brother Demetri tries to save Minsk's son Little Demetri from Bimbolurlina he is killed in a very brutal manner, Minsk and Edward are there for him in his final moments, his last words to Edward 'Even though I never liked humans I now see you as worthy mate to my sister, Farewell My Brother.'