This is based on opinion. Please don't list it on a work's trope example list.
Tear Jerker / Beyond: Two Souls
The aftermath of "The Mission". Gemaal Sheik Charrief and his men are dead. Jodie walks in, camera in hand, to confirm the mission's success. Then, in bursts little Salim, who kneels in horror and grief beside one of the bodies, desperately shouting something over and over. You don't have to understand the language to realize what's going on: Jodie just killed his father.
It gets even worse. In the CIA helicopter on the way home, a shell-shocked Jodie turns on the news, just in time to hear a massive Wham Line being dropped. Charrief wasn't a warlord, like Ryan had told her. He was the democratically elected president, who many hoped could end the years of conflict in his country. The horror at what she's done, combined with being betrayed and manipulated by Ryan, utterly devastate Jodie.
Earlier on, there was a bit of bitterly ironicForeshadowing. In "Homeless", if he finds out that Jodie is on the run from the law, Stan will say that he doesn't need to know why. As long as she hasn't killed anybody, that's fine by him. One can only imagine how much that remark must have hurt Jodie.
Dawkins' reaction to the death of his wife and daughter, as well, as Jodie's description of her life without Aiden. As anyone who ever lost a close relative knows, those are extremely faithful depictions of what the first weeks (if not months) afterwards feel like: like having a piece of you torn out, so you just want to curl into a ball and weep, but no matter what you do, the pain simply doesn't go away.
Then in the chapter "Black Sun" Nathan deactivates the containment field, so that the Infraworld will merge with the real world; the living and the dead can be together at last. When Jodie catches up to him, some of the dialogue choices will see Nathan choosing to take his own life. Jodie then sees Nathan's spirit reuniting with his wife and daughter. He then looks over his shoulder at Jodie, looking more like the Nathan she knew as a child, and asks her to destroy the condenser.
Nathan: Please Jodie. Do it for me.
During the begging sequence in "Homeless", you can have Jodie play a heartrending rendition of Beck's "Lost Cause". You can just hear how broken and world-weary she sounds during the performance.
"Homeless" also gives Jodie the opportunity to channel the ghost of Stan's deceased wife Nancy. Seeing him talk directly to her about how empty and miserable his life has been without her is heartwrenching, but the fact that the encounter gives him the strength he needs to move on can produce tears of a different kind.
If the Beyond ending is chosen and Ryan survives, watching his reaction to Jodie's death is absolutely heartbreaking.
In the Beyond ending in which Jodie chooses to die rather than return to a world without Aiden, she finds herself returning to the world as a spirit to look over those she cares about. In one scene she visits Cole, and writes a message to him on his computer screen, informing him that his 'little Princess is still here'.
If Cole is dead in Alive, Jodie puts a drawing of a princess on his grave.
When Jodie is taken away from Cole and Nathan by the CIA, she's sobbing as she's packing her bag with what few posessions she's allowed to take, and it's heartbreaking because you have to control her throughout.
When Norah, Jodie and Aiden's birth mother, is screaming and pleading for her daughter as she's taken away from her just seconds after she's born. Then there's the fact that Aiden was stillborn.
Also when Norah is later mercy killed by her own son, instead of having to suffer being tormented by the dark spirits in her comatose state. She even smiles when she passes away.
The Party. Enough said, probably. The dumb girls and guys belittling Jodie, physically hurting her, calling her a liar about having powers, the English guy bringing everyone on board with calling Jodie a slut and the whole group finally calling her a witch and locking her in a closet. If the player does take revenge, they deserved it for hurting Jodie, drinking, doing drugs and being morons.
The Dinner chapter can potentially end on a sad note in a few different ways:
If Jodie was nearly raped in the Like Other Girls chapter, Jodie will have a panic attack at the end of the date, remembering her traumatic experience, leaving Ryan to excuse himself and leave the apartment.
If the player decides to have Aiden sabotage the date at every opportunity he gets, and Jodie rejects Ryan's kiss (assuming they even get that far), Ryan will excuse himself and leave, leaving Jodie in tears and frustrated at the failed date.
"The Experiment" may cause a My God, What Have I Done? moment at the end of it if the player really decides to go overboard with Aiden knocking things over. While it's funny at first, watching the lady on the other side jump as things from her point of view just randomly fall over, by the end of it Jodie is screaming and the woman is rapidly coming very close to having a nervous breakdown because she's trapped in the room as Aiden tears the place apart.
The end of "Haunting". Nathan pleading with Jodie to have his wife and daughter talk to him again just breaks your heart.
Near the of the game, it is revealed that Nathan has been keeping the souls of his wife and daughter trapped between dimensions, obviously in pain, for Lord knows how long and has been visiting them every night but he cannot actually communicate with them beyond seeing them so he asks Jodie to help him speak with them. If she complies, the soul of Nathans wife begs him to let them go and just let them die. Nathan delusionally refuses to listen to her, insisting that Jodie is saying it, not them, because obviously his wife and child are happy and they would never say something like that, right?