This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / The Originals
The fate of Katie and Thierry, two star-crossed lovers caught in Klaus's plans. Katie ends up with her neck snapped and Thierry ends up entombed for the next one hundred years. The worst part is that Thierry was willing to walk to his doom with some dignity. But after Katie's death, he ends up sounding so defeated.
Cami begging Klaus not to basically MindRape the trauma of the Murder-Suicide of her brother, because it is a part of what makes her who she is. Both are in tears over this violation. The worst part is that Klaus was trying to do something nice for her.
The Sowing for the Harvest Ritual: three witches killed, including Sophie's niece Monique while Davina and Sophie tried to stop it. Had Marcel not intervened, Davina would have been dead as well.
That's not all either: after the Harvest Ritual, the four young girl witches were supposed to resurrect, though Sophie didn't believe it at the time. She changes her mind afterward when she noticed it was working and when Jane-Anne tells her that with Davina still alive, none of the other girls will resurrect, which includes her daughter Monique. If Davina isn't killed before time runs out, then Monique would have sacrificed herself for nothing. Guilt-ridden, Sophie vows to her sister to finish the ritual and bring Monique back whatever it takes, and together, they set up the plan that became the premise of the show. A plan that cost Jane-Anne her life, and may very well cost Sophie her own.
Davina retelling of the Harvest to Elijah is told in a borderline broken monotone, sounding like a victim of PTSD. She then reveals on that day she lost her faith in her people. People like her mother and others who just stood there as their daughters begged not to be slaughtered like animals And her fear that if they lied about the Harvest itself, how can she trust them in regards to the supposed resurrection? In the end the plain fact is she doesn't want to die.
Hayley finds out that her baby's blood can be used to sire hybrids, and assumes that that's the only reason Klaus is interested in his child. When Elijah and Hayley confront him about it, he actually looks hurt. It's not unreasonable to assume that of someone like Klaus, but in this one instance, he genuinely cares about the baby and concludes his heartbreaking speech about how even his own child will see him as nothing more than a 'bastard'. And then he bites Elijah's neck.
The Funeral for Marcel's people who decided to stand with him against Klaus. Diego and others is dousing bodies with alcohol for a funeral pyre while Marcel looks on mournfully and a haunting funeral dirge is played by sax.
Elijah's howl of anguish as he clutches the body of his lover Celeste. The memory of it (and how deeply he loved her) affected him so much that while sick with fever from Klaus' bite, his time with her was what he hallucinated amongst all his other memories.
After Klaus found out about Marcel and Rebekah's relationship, he daggers Rebekah for fifty-two years. It's bad enough that Rebekah has to deal with the fact that her own brother essentially took a generation of life from her. But that's not what makes her break down: it's the fact that Klaus tells her that he offered Marcel a deal - hold onto his love for Rebekah and live his days as a human, or renounce her and become a vampire. Right on cue, Marcel walks in...not a day older than the last time she saw him.
Klaus confronting Elijah and Rebekah about their respective betrayals (him believing Tyler's claims about a plan to use the baby to make hybrids, her plotting against him with Marcel) at the end of "The River in Reverse". He wasn't just angry, he was so genuinely hurt, he actually shed tears.
Davina weeping over over the dead body of Tim who Klaus just used to poison Davina as a back up plan. He intended her to be killed as well but Marcel had a back up plan to his back plan. She ends up begging him to wake up, and basically watches the last bit of normal from her past life die in front of her.
"Après Moi, Le Déluge" had quite a few:
Marcel is comforting a dying Davina as she is making a choice to complete the Harvest in order to prevent destroying New Orleans when she overloads.
Davina: "Marcel, it's okay."
Marcel: "No, I failed you..."
Davina: "I'll die whether I do this or not. Now, the only option is whether I take everyone with me. If you look at it that way, it's kind of selfish not to do it."
Marcel: "There has to be another way; this is not the way it ends!"
After a year struggling, wrecked with guilt at her intervention preventing the original Harvest and the cost of her sisters life. Sophie has completed the Harvest and can finally resurrect her niece via the reaping.
Sophie: "We call upon the Elders to resurrect your chosen ones."
Nothing happens, and we cut to the still dead bodies of the girls. Marcel, Klaus, Hayley, Rebekah, and Elijah search for signs of life from the girls.
It gets even sadder for her afterwords. In the next episode, we find her drowning her sorrows, and in the episode after that she finally meets the apparently newly resurrected Monique... only to try to get her out of town and to safety in vain. The episode ends with Monique, of all people, killing her Aunt Sophie, citing a lack of faith on Sophie's part for the reason before walking off with the Big Bad Duumvirate of revenge-obsessed witches. At this point, Sophie's eight month long tragic quest comes to a tragic end.
1.14 gives us Rebekah: alone, sick with werewolf venom, running through a creepy-ass Abandoned Hospital in a futile attempt to stop Genevieve from showing Klaus that she and Marcel had conspired to bring Mikael to New Orleans in 1919.
Genevieve deserves a mention here as well. Before becoming twisted and cold with vengeance, the flashbacks in this episode showed that she used to be a sweet, naive girl who made the honest mistake of trusting Rebekah's overtures of friendship. Once Rebekah got cold feet about summoning Mikael, and Genevieve told her the spell was irreversible, Rebekah infected her and her friend (who had been possessed by Celeste) with influenza. Then she compelled the orderlies to put the women in quarantine until they died horrible, bloody deaths from the disease.
Klaus' reaction when he sees the truth. He howls and cries, but as Genevieve shows him more memories, his anguish becomes more muted. He's on the verge of tears throughout. And then he picks up Papa Tunde's knife and goes hunting for Rebekah.
And again when Elijah shows up and stabs him with that same knife before he can do the same to Rebekah. The look on both their faces...this is going to be an event that will make or break this family.
And Episode 1.15 makes this even worse. In the flashback of the day Mikael ran the Originals out of New Orleans, Klaus had finally given his blessing for Rebekah and Marcel to be together. Their betrayal had ultimately been for nothing.
The flashback of Rebekah in the aftermath of Mikael driving them out of New Orleans. She's stricken with grief and horror at what she has done, and the consequences of it (i.e Marcel apparently burning to death in the opera house).
Even though she was ultimately done in by her own hatred of the Originals, Celeste may have ultimately won, as the episode 1.15 ends with the Originals staring each other down. Klaus with an indestructible white oak stake (the only thing that can kill an Original vampire) and going full hybrid, with Elijah and Rebekah on the other side gearing up with Papa Tunde's knife as their weapon. One thousand years, and ultimately the three siblings seem to have reached a point of no return.
1.15 is one big Tear Jerker for the Originals themselves. The flashback had shown that Klaus had done the impossible and had united all the supernatural and human factions in town, Rebekah and Marcel can finally be together, and the siblings are finally happy. Then Mikael comes to town and destroys their home and everything they'd built since they arrived centuries ago, in just one night. All they can do is flee from their father, having to go through the anguish of losing yet another home. And what makes this particular one sting, is that they thought that they'd lost Marcel as well, the closest person they've called family outside of their own blood.
In the aftermath of 1.15, Klaus and Rebekah realizing that they've suffered too much damage - from their father and from each other - to stay together, even if they still love each other. Klaus allows Rebekah to leave New Orleans for good, and she takes that chance.
The various flashbacks to the Originals' lives before they were turned into vampires. Klaus and Rebekah had always been close to each other since they were children, with Rebekah even going so far as to sneak into Mikael's room to kill him in his sleep for his vicious abuse towards Klaus, which she would have done if Elijah hadn't intervened.
And then there's Davina. As punishment for helping Marcel against the witches, the spirits of the ancestors kept her isolated and alone. While the other three Harvest girls were trained and comforted, she was somewhere 'cold and dark.' And when she wasn't alone, she was tormented by the ancestors and threatened with terrible punishment if she ever uses her powers to help vampires again.
It gets worse in the following episode, where Davina is afraid to even use magic due to her trauma. Worse, the rest of the Harvest Girls - including Monique, who used to be like a sister to her - aren't even aware of how the ancestors tortured her, or that they even care. They bully her and call her weak. Even in her community, Davina is still and may always be an outsider.
Poor Marcel , in less then one day he lost the woman he loves, had to give up the girl he swore to protect in order to save her sanity. Is exiled from the only home he has ever known, lost his kingdom , his people and faces an uphill battle to regain his dignity.
Klaus' speech about how vampires are the 'antithesis of unity'. It's a thinly-veiled commentary on his own family, and offers a hint as to how much he misses Rebekah.
Elijah killing Thierry to teach Marcel a lesson for violating the terms of his exile. It's the second time Marcel has ever wept on-screen (the first being Davina's death). Mitigated in that Thierry's death is what finally convinces the other vampires in the Quarter to join Marcel in what may be a fatal rebellion against the Originals.
Klaus' face in the aftermath of Marcel's surprise attack at the witch festival. When the lights come back on, he sees Hayley on the floor, looking bewildered. As he starts to go to her, she calls for Elijah instead.
And in the same episode, Elijah bitterly telling Klaus that he's denied every impulse he ever had for his own happiness just so he could devote himself to the redemption of his brother. And in the face of him finding out that Klaus had been meeting with the werewolves in secret, Elijah has had enough.
Elijah: "If the definition of insanity is doing the same thing repeatedly and expecting different results, then surely my quest for your salvation ranks me as one of the maddest of men."
The death of Father Kieran. He'd been in transition in an attempt to stop the hex, and just as he's made the decision to die with peace, the hex comes back. He attacks Camille and almost kills her before Klaus snaps his neck and stakes him. Camille is all but catatonic at the end of the episode, and numb with grief for the next.
There might have been few people who don't feel a little bit sorry for Genevieve. She doesn't want to kill Klaus' unborn child, and pleads in tears with the witch ancestors for any alternative, that she doesn't want to be a monster for killing a baby. Everything she's done since being resurrected becomes less a calculated move for power and more of the desperate actions of a woman who doesn't want to die. To make it worse, the ancestors physically torture her until she finally caves.
Klaus at the end of 1.21. He's been outgambitted by people he'd never seen coming (Francesca and Genevieve), and in his single-minded determination to eliminate Marcel, his home is filled with vampires bitten by werewolves, his blood is being used so that when a werewolf suppresses the urge to turn at moonlight he loses his strength, he's lost control of the city, Marcel might be permanently estranged from him, and worst of all, the witches have taken Hayley so that his unborn child can be sacrificed for their power. Is it any wonder that he screams at the end of the episode? Oh, and to make things worse, Davina has agreed to resurrect Mikael, unbeknownst to him.
The season finale is basically one huge tearjerker on top of another:
Klaus incapacitated by the witches and being forced to watch as they first steal his daughter and then kill Hayley. And then Elijah finds her body in the church and completely loses it. Subverted in that since Hayley died with the baby's blood in her system, she woke up in transition and is now a hybrid.
Elijah breaking down when trying to find the baby. Having believed Hayley died and they'd never find the baby, he actually cries and tells Klaus how he let them in to his heart, which is something he never does.
Marcel, after rescuing the baby, takes her in the hopes he can use her blood to heal his men. Unknown to him, Davina has resurrected Mikael...who feeds only on vampire blood. He goes back to the compound to find every single vampire dead. Basically after everything he did to protect his Vampire family , he ended up losing all of them. Both his lieutenants Deigo and Thierry who he treated as brothers. Including every single New Orleans Vampire has been killed . Leaving Marcel the only New Orleans Vampire left in the City.
Hayley comes up with the idea to give her daughter up so she can be safe while herself and the Originals deal with their enemies. In order to do that, they have to pretend that she was killed during the Guerrera werewolf attacks, and then say goodbye.
And while she's making that heartbreaking decision, Hayley has to drink her own child's blood so she can survive and transition into a hybrid. Her anguished face as she pricks the baby with a needle and the baby starts wailing....
Klaus' and Rebekah's reunion as he gives little Hope Mikaelson to her for safekeeping.
Klaus telling Camille that they can't be friends anymore, as the danger she faces from just associating with him is too much.
Finally, the revelation that Esther Mikaelson has taken control of the ancestor witches, and that it was her idea to sacrifice the baby. Even in death, Esther won't stop hunting her children, even willing to kill her own granddaughter to get what she wants.
The state of New Orleans and the Mikaelson family in general at the start of the second season. The Guerreras have all but driven the vampires out of New Orleans, Klaus has locked himself in his home for several months and still suffers during the full moon when the kyanite stones sap his strength so the wolves don't transform, Hayley has distanced herself from both Elijah and Klaus...and it's clear that their collective grief at losing Hope is not just for show.
Special mention goes to Hayley not just for losing her baby and her pack, but losing what was left of her humanity. Being a hybrid makes her feel like a traitor to her family, unnatural...and she thinks that the reason Elijah has cooled down on their blossoming romance is because he loved her when she wasn't a 'monster.'
Then there's the fact that despite being a hybrid, Hayley voluntarily turns into a werewolf during her nightly rampages. This, in a universe where turning has been established as horrifyingly painful, serves as a clue as to her fragile state of mind as her desire to hold onto her werewolf heritage.
Despites mentoring Marcel as a child, and loving him as a favoured younger brother, Elijah is forced to give Marcel the cold shoulder and break the boy's heart. All so that Marcel would return under Klaus' wing, and that Klaus could retain his link to his humanity.
Klaus learns that the starling necklace his mother gave him - one of the few happy memories he still has of his childhood - was enchanted to suppress his werewolf gene. Esther only gave him the necklace because she was afraid Klaus would activate the curse and expose her infidelity. His heartbreaking rant to her when he realises this is such that she can't even look him in the eye, despite her justifications for it.
It's also heartbreaking to see how easily Klaus loses control when he faces either of his parents. All it took was ten minutes in the same room with her, and Klaus almost regresses back into a childlike state in his anger. However much he postures and threatens to kill his mother, it's clear that she's still got a hold on him - indeed, on all the Originals - that he can't shake.
Thanks to Esther, Elijah's darkest secret is exposed. That a thousand years ago, Esther did not murder Tatia the love of his life, but a stressed and newly turned Elijah who lost control during a confrontation with her when she was wounded. He literally chased her down, and savagely drank her dry. Distraught and horrified, he turned to his mother who erased and reshaped his memory with his permission. His sin was hidden behind both a physical and symbolic Red Door . This is the reason why Elijah is repressed and values self control, and also reveals that his tendency to value other peoples joy and happiness over his own is self punishment for an act he has repressed for centuries.
In the flashback of 2.06, Freya's screams for her mother as Dahlia carries her away.
Klaus killing Ansel. He sincerely wants to believe that he can trust his father, but has to do what's best for his daughter, by not letting the secret get out.
Esther's reaction to seeing his corpse. She's lost the man she loved a second time.
Rebekah sadly noting that she knows she has to give Hope back to Hayley when it's safe for her to return to New Orleans. She even tells Elijah that her time with Hope makes her wish that she could have children of her own.
In a way, Finn telling Cami that the reason Esther chose her to be Rebekah's Soul Jar is that she's physically healthy...and alone. It's a stark reminder that outside of Klaus, Marcel and Davina, Cami doesn't really have any family or friends to turn to, especially since the death of her uncle Kieran. No-one would notice if Rebekah takes over her body and she acts differently, because she doesn't have anyone who would even tell the difference.
Plenty in the mid-season finale:
Klaus wanting to burn the first family picture with Hope in it as he doesn't want to her to be in danger.
In a twisted way, seeing Esther in transition is pretty painful to watch. It's never fun to see a grown woman cry, and Sonja Sohn's portrayal makes you feel it, too.
Aiden having to break Josh's neck to stop him from attacking Davina in 2.12
Seeing Kol beg Finn for mercy after he's discovered trying to betray him, and then the terror on his face when Finn curses him to die in less than a week.
It gets worse in the following episode when he reveals that Finn has put a hex on him. There's no way to stop him from dying.
The way he emphatically doesn't want Davina to help Klaus find Hope. Not because it's too dangerous, but because he doesn't want her to know that he's sick.
His actual death is this: slow and agonizing, until he finally succumbs with Davina and the Originals devastated by it.
Hayley stopping Elijah before he can confess his feelings to her on the eve of her wedding, and then telling him that she sees a chance for happiness with Jackson, even though she loves Elijah. Elijah even cries as Hayley walks away.
The fact that Freya was the one who got rid of Finn by sealing his soul inside her pendant. Sure, he had it coming, but to have that done to him - for the only sibling he truly loved to put him in yet another box - must have hurt. Hopefully he's either suspended and unaware of his current predicament.
She didn't do it to punish him and he knew it, she did it to save his life. Klaus wanted to kill him and Elijah didn't know how to exorcise Finn from Vincent.
The aftermath of Finn's possession of Vincent Griffith, who seems like a genuinely good guy that now has to deal with losing nine months of his life as well as all the atrocities Finn committed while in his body, including attempted infanticide.
Freya watching the love of her life be murdered by Dahlia's magic six hundred years ago, and then accidentally aborting her child in a failed suicide attempt to get away from Dahlia herself.
Seeing Freya horrific past goes to show that none of the Mikaelson children grew up untouched by pain and tragedy. Each and everyone are scarred by their past. Klaus, the target of his father's wrath. Elijah, the brother always overcompensating for his own faults. Kol, the youngest and stripped of his magic. Rebekah, the girl who only wanted to be loved and Freya, the girl given away to a mad abusive aunt so that her other siblings would be spared. Even Finn, the keeper of his mother's secrets, traumatised by his sister's abduction and least respected of the Mikaelson siblings. All of them have traumatic pasts.
Mikael's second death. He is caught off guard by a sneak attack, not even given a chance to fight . Klaus is crying and emotional before staking him, telling Mikael that he only wanted him to be a father to him and wanted to know why he hated him, Mikael himself seems to not know anymore, simply saying "I don't know, I just did". Mikael gives a Freya one last look and tells her he is sorry and that he loves her before Klaus stakes him. Freya's reaction is just heartbreaking too, reunited with the only parent she loved and he is killed only episodes later.
Even more brutal its the one true honest moment between Klaus and Mikael. Without pre-tense or ranting, and it Mikael confession that there was no chance of Klaus winning Mikael approval or love. Simply put that he has always hated Klaus, just because. The look of emotional pain on both their faces is heartwrenching.
Aiden's horrific death at the hands of Dahlia. Right after he confesses to Jackson about being Klaus' spy and made plans to leave New Orleans with Josh.
Dahlia kills Aiden to make it look like Klaus did it. And when confronted with Aiden's body and Jackson's accusation, Klaus confesses to the deed. It's only when Cami confronts him that he tearfully admit he didn't do it: it's just easier to let everyone think he's that much of a monster, so he can use their fear to his advantage.
Dahlia's backstory, which explains both her need for family and for power no matter what. Both her and her sister were captured by a Viking raiding party that slaughtered their village and enslaved them. Both sisters swore to be there for each other no matter what. Dahlia was abused by their captors and forced to do dark magic for them, in return for Esther to escape their torment and enjoy some sort of freedom. But that wasn't what broke Dahlia. On the day Dahlia was planning to escape with her sister, Esther revealed that she was planning to marry one of their captors. Not only that, but she was abandoning their magic: the very thing that Dahlia used to keep them both alive. Esther left her heartbroken sister alone in a hut without family, in pain and yearning for power to make sure it never happened again.
The memory of Esther's betrayal is still fresh in Dahlia's mind. She still cries for her younger self when she shows Klaus that memory.
Klaus' predicament in 2.20. Daggered by his siblings for a murder he didn't even commit, then dragged into his deranged aunt's head and told that unless he hands Hope over to her, her hybrid witch powers will consume her and the world. Then he wakes up just in time to hear Hayley leave a voicemail, saying that she doesn't want Hope to be a Mikaelson and inherit a thousand years' worth of her father's enemies. Even worse, Rebekah and Elijah agree with her, that it's better if Hope is raised far away from them. Faced with losing his only child forever, Klaus goes to Dahlia and accepts her deal, committing to murder not only Hayley but his surviving siblings as well.
While the second season finale ends with the current Big Bad being killed, there's still plenty of sadness to go around:
After a thousand years of trying to redeem his brother, Elijah reaches the end of his rope with Klaus, whose gambit to fool Dahlia meant that Gia was burned to death and Hayley becoming a victim of the Crescent Curse. He punches him in the face and tells him that he washes his hands off him. The only reason he's still in the manor is because Hayley begged him to raise Hope so that Klaus isn't the only father figure she knows.
Elijah's barely contained grief at losing Gia. He still loves Hayley, but he was clearly falling in love with her as well, and had to watch Klaus compel her to take off her daylight ring and burn to death.
Davina finally has a chance to bring Kol back, only to be tricked into resurrecting Esther. Her hate and grief towards Rebekah and Elijah is palpable.
Rebekah having to give up her witch body to further Klaus' gambit to stop Dahlia. She has to break her promise to bring Kol back, and has lost a chance to have a family of her own.
Heck, even Dahlia gets one when she's confronted with Esther. Her voice cracks when she sees her sister again after a thousand years with raw emotion.
The sight of Esther and Dahlia's bodies locked in an embrace, Dahlia finally forgiving Esther for her betrayal before they die.
After three months of living with the Crescent Curse, Hayley gets a chance to storm into the Mikaelson estate and have a drag-down, no holds barred and highly emotional fight with Klaus, screaming at him and crying for everything he's done, all because she wanted a better life for her child. She only stops when Hope walks in, and breaks down crying when she realizes that she missed her daughter's first steps. Even Klaus looks briefly guilty for what he's put Hayley through.
Lucien's horrific torture at the hands of Tristan, just because he was in love with Aurora.
The flashback to Aurora's cruel rejection of Klaus when he asks her to run away with him is bad enough. Then comes the reveal that Elijah had accidentally compelled her: first to reveal Klaus' matricide, and second to see him as a 'monster' and reject him. It's also heavily implied that Aurora's coldness towards Klaus pushed him into embracing his darkness and becoming the monster he is today.
Davina being exiled from her fellow witches in season three. She marches along a line and as she passes, each with turns their back on her and each step brings her a flash of pain as her connection to the elders is taken away and she's broken into tears by the time her march is finished.
Episode 10 of the third season brings a double gut-punch by killing off Jackson and Camille, the only two unambiguously good characters in the show. Jackson has his heart ripped out in front of Hayley by the Stryx. Cami had been compelled by Aurora to kill herself, thus waking up in transition. By the end of the episode, she's become a vampire and her formerly golden-hearted personality has now been overshadowed by her vampiric instincts.
The next episode makes their loss more apparent. Camille takes to vampirism with so much gusto that even Klaus is horrified at her sociopathy. And Hayley is an absolute wreck and is being eaten alive by guilt over her inability to save Jackson. As she brokenly tells Elijah:
Hayley: "My husband died because he loved me. And loving any of us is a death sentence, isn't it?"