Tricia's death, and the subsequent ways that the inmates deal with their grief.
Taystee's confession to Poussey about why she couldn't handle it on the outside.
The reason Janae is in prison. She was a promising athlete who fell in with a bad crowd. She ended up robbing a store with her boyfriend, who managed to escape in the chaos, leaving her behind.
Suzanne weeping during Larry's radio show and earlier that episode, when she asked Piper why everyone called her Crazy Eyes.
The reactions from Claudette and Piper herself are also brutal.
Pornstache inadvertently confessing his loneliness and self-loathing to Bennett.
Chapman's breakdown in solitary during the 'Fucksgiving' episode. She may or may not have been hearing voices.
Miss Claudette losing her appeal after excitedly dreaming of the things she'd do after gaining freedom. She flies into such a rage that she starts choking the guard Susan. The inmates comment that as soon as you lay your hands on a guard, you're moved to maximum security, and you never get out.
"Your tits are better than mine." The whole scene, but Sophia's wife's comments, dear God.
"Why do people call me Crazy Eyes?"
Maria is so excited to meet her baby that she doesn't realize it'll be taken from her shortly after its birth.
Yoga Jones' crime: She was drunk, standing in her marijuana field at night with a shotgun hoping to kill any deer that might try to eat her crop. She shot at something moving in the dark...only to learn that it was a child. The boy had tried to run away from home because his father took away his video games. And he lived nearby, so its possible that she knew him. No wonder Yoga Jones is so haunted by it.
Larry's reaction when he discovers that it was Piper who came on to Alex, not the other way around. The look on his face is heartbreaking.
The way his voice breaks when he asks, "Do you love her?"
"Bitches gots to learn." Piper's speech to Dina about how prison will ruin you simply by forcing you to confront yourself effects not only Dina, but all of the inmates, kids and guards who were listening outside.
Even though Pennsatucky is the Big Bad, the sight of her panicking and crying out when she ends up strapped to her bed in Psych is devastating. And even though she didn't become religious until after she got a Christian lawyer, her anger towards God for believing that He abandoned her during a time when she genuinely believed she was helping people was pretty harsh, too, considering religion was clearly just as much of a comfort for her as it was a tool.
Everyone believed that Flores is insane, talking to herself in the one stall with a door on it. It turns out she was just talking to her boyfriend via a hidden cell phone. She's overjoyed when she gets a visit from him and it's a cute moment... Until Piper has to turn in the cell phone to Healy in order to try and get the track open. Flores is so upset when she realizes that her connection to her boyfriend is gone that she breaks the bathroom door and is taken away, crying. And then we see her later in Psych...
The truth about Morello's backstory - she and Christopher were never actually engaged, and he never loved her. They only went on one date and she basically stalked him prior to her incarceration. Yet she still deludes herself into thinking the opposite.
This becomes more tragic when he comes to visit her in prison, loudly announcing to everyone there exactly what she did.
When Jimmy (the elderly senile woman) is taken away after breaking her arm for a "compassionate release" and she cries for help from "Roberta" (what she calls Piper). Compassionate release meaning being thrown out onto the streets and left homeless to avoid having to pay the costs of caring for a senile woman
Piper's entire relationship with Jimmy is both tearjerking and heartwarming; she starts looking after her, cutting up her food for her, and listening to her stories about Jack. It's most likely because Piper has learned that her grandmother is dying. Jimmy's senility is very sad in itself, especially since she isn't getting help for it; the other inmates are the ones taking care of her.
When Piper looks the other way when Lolli is beaten by the other women.
Rosa's backstory when both men that she falls in love with end up dying. She thinks that she's actually cursed, and panics when the boy she's formed a friendship with through their chemotherapy sessions appears to get bad news about his cancer. She even states that all of the men in her life end up dying, and seems genuinely upset until she learns it's good news; the boy has gone into remission. The scene becomes a tearjerker for an entirely different reason then.
When Taystee confronts Poussey and pushes her down after Vee throws her out of the group. The expression on Poussey's face and Taystee's subsequent reaction is both tearjerking and heartwarming.
Soso being forced to take a shower. Sure, she's naive and irritating, but the utter look of defeat on her face is genuinely heartbreaking.
For Pete, being told that his wife is leaving him for his close friend.
One for Fig of all people, when she walks in on her husband and his staffer kissing. Even though she's a total jerkass, it was sad to see her like that.
On a more subtle level, Taystee as a character. As the first season hinted at and the second season further explores, she's very smart and charismatic but spent her life trapped by her racial and class background, with Vee the only person who gave her a chance.
It is sad to see as the season goes along that Vee really doesn't genuinely care for Suzanne and that she's only using her for for own advantage.
The scene of Suzanne sitting on her bed clutching the pack of Uno cards, crying her eyes out with no one comforting her. Its obvious she's just come to the realisation that Vee, her only 'friend', was using her
Generally a lot of Suzanne's scenes this season, especially the flashbacks of her as a kid, being isolated.
After Red is brutally beaten by Vee and her girls while Norma is forced to watch, and she is lying on the ground, bloody, whimpering, and sobbing. By extension, seeing Poussey in a similar position when Vee lets Suzanne beat her up and leave her crying in the bathroom.
Piper finding out that her grandmother passed away just a short time before she managed to get off on furlough, which had been almost impossible to achieve.
The anger and hostility that the other inmates have against Piper for her getting furlough is a Tear Jerker in itself; at first it seems like they're just jealous that she gets to be free for two days and do whatever she wants, but later on it's clear why they're upset: they had to miss their own share of tragedies, such as missing the birth of grandchildren and Poussey losing her mother.
Black Cindy of all people has one when her flashbacks show that she rarely visits her sister and when she does, she gives her a stolen iPad. And when she gets called out it's revealed that her sister is actually her daughter and she wants to take her back but it's clear she wouldn't be able to handle it. It makes you look at the usually upbeat woman in a different light.
Taystee's relationship with RJ, someone who she likely harbored romantic feelings for. She believed that he died as a result of carrying a weapon, even after Vee tells him not to. It's later revealed that Vee found out he was planning to start his own dealing operation and had him killed by her corrupt cop buddy. She was supposed to be like his mother!
A subtle one. Up until '40 OZ of Furlough,' Red has been working on earning the forgiveness of her prison family and reestablishing her reputation while also dealing with her own family, none of whom have visited save her son Vasily, and she is worried that something might be wrong. When Piper receives furlough, Red asks her to stop by her husband's business if she has time to visit. When Piper does visit, it's apparent that the shop has been out of business for a while.
Even sadder is when Piper can't bear to tell Red the truth, and Red seems so happy when Piper spins a tale about visiting the shop. It's a real bitch, knowing she's going to eventually find out.
Compare Brook's first few conversations with Piper, to their last one in the finale. Brook is a lot less warm and bubbly, and you can tell prison has really broken her spirit.
After a season of getting colder and insisting to her dad that she is who she truly is while in prison, Piper admits that she doesn't like who she's becoming once Soso tells her how alone she feels, and that prison only changes people for the worse.
Piper's pained screaming at the end of "Thirsty Bird", when she realizes that by taking Alex's advice, she just missed out on her chance to get out of prison early, and may face additional prison time for perjury while Alex walks free.