This is based on opinion. Please don't list it on a work's trope example list.
Tearjerker / The Amazing Spider-Man 2
Gwen's death. The web Gwen is holding onto snaps at the same moment Peter knocks Harry out, and she begins falling to the ground. Peter dives after her, and fires a web which snags Gwen by her midesection, before grabbing a pipe to stop himself from falling. Unfortunately the web still stretches enough for her head to hit the ground and kill her. Peter then drops himself down to the ground, and as he's cradling her body, the realisation slowly sets in as he goes from asking Gwen if she's okay, to desperately pleading with Gwen to stay with him, and finally breaking down sobbing upon realising she's dead. The music does not help, and Andrew Garfield's absolutely agonizing performance is like an emotional sucker-punch to the stomach. And the worst part of this scene? It's taken straight out of the pages of The Night Gwen Stacy Died. The slow-motion really helps the feeling set in.
In the original comic, Peter Parker keeps his mask on the entire time upon the discovery that Gwen is dead. Which is kinda Narm-y. Here he removes his mask, so we're forced to see Peter's reaction.
And Gwen's face as she's falling. You can practically see her life flashing before her eyes. And she closes her eyes when she is near the ground - it's like she knows what's coming, and there is nothing Peter can do to save her.
The gasp she lets out after the web snaps is more painful to hear.
Her last words:
When she falls, Peter shoots a web out to her which takes the form of a hand (in a way, his own) trying to reach for her. It's beautiful to see, but still sad given the situation.
The shots of Gwen just after she suddenly dies are HAUNTING. When you see her just hanging there and then the parts of the clock falling around her, and the high angle shot of her dead body hanging there by Spider-Man's webbing, it's just incredibly sad to see.
Something about the fact that Gwen's death being inside a dark clock tower instead of the George Washington Bridge like in the comics seems like an even more sadder setting than instead of the top of the bridge.
Some people that have already watched the movie believe something else had ultimately killed her in the end: either the whiplash effect, the sudden stop, the shock of the fall or her head hitting the ground. Much like the comics, the film makers have seemed to have raised the questions regarding Gwen's death again, where you don't know what exactly killed her but that ultimately there was nothing Spider-Man could've done to save her.
The jump cuts illustrating the passage of time, as Peter stands at Gwen's grave day after day.
There's also how hard he tries to save her only for it to end in failure. Special mention to him lodging his foot to jam the clock parts; he literally put himself through soaring pain, and it's still not enough to save her.
Take a close look at the Stacy Family at Gwen's graduation, and then her funeral - Only two of her three brothers are at the funeral, the youngest being the absent child.
When you think about it, her family has just lost the father, and now the only daughter in the household. Here's hoping that we see them recovering somewhat from such a great loss in succeeding films in the reboot.
Speaking of Gwen's father, remember that the last words he said to Peter was to keep Gwen away from the dangers he would face as Spider-Man. Peter was literally haunted by the image of Captain Stacy throughout this film. And now his daughter's dead because he didn't listen to his words. God knows the amount of guilt that must have added to Peter.
The fact that this time, it wasn't Spider-Man's arch foe the Green Goblin (usually being Norman Osborn), a complete maniac, who killed her. This time, it was Peter's best friend Harry Osborn, who went insane, took up the Green Goblin identity and tried to kill Gwen in revenge for Peter not giving him the sample of his blood that would have killed him. That's the man responsible for Gwen's death, and it just has to be eating Peter alive that he lost two of his best friends in one day.
The fact that there's no gasping for breath, coughing, or Last Words from Gwen as Peter holds her. The suddenness and absoluteness of her death makes it all the more tragic as Peter is basically already pleading with a corpse.
The comic version left a sort of discretion shot in that it wasn't apparent immediately that she'd died, and we only realized when Peter did. Here? No discretion shot at all. we have to stay with Gwen the whole way down, and as an added bonus, we get to hear the sick thud her head makes as it smacks the floor.
In the alternate death scene, Harry elicits a mocking laugh while hearing Peter sobbing, making the latter snap and beat the former to near death.
Gwen's graduation speech, my goodness. For anyone who didn't know Gwen's fate, it'll become Harsher in Hindsight. But for everyone who knew or suspected that her arc would end as it initially does in the comics, it's very much a Foreshadowing tearjerker. She mentions thinking they're immortal, then says that "what makes life valuable is that it doesn't last forever, what makes it precious is that it ends." She also says that "time is luck", which becomes harsher in hindsight/ironic when her death takes place in an old clock tower.
Pretty much everything to do with Max Dillon prior to, and for a while after, his transformation. Here's a man who's either ignored or bullied by almost everyone he meets, has his birthday forgotten by everyone and is pretty clearly pining for any kind of genuine human contact from anyone. Not to mention having all his work on the new electrical stolen and used by Smythe. It's not hard to imagine that the kind words and actions of Spider-Man are the first he's had in years and to see him place so much importance on them is heartbreaking.
When he sings "Happy Birthday" to himself. It's a reminder that there is no one there for him. Not even on his birthday.
Someone has a video camera in Times Square, and puts Max on the big screens. It doesn't even matter to him that he's transformed and people are terrified, he's just amazed that they're noticing him at all.
Max: (awestruck) You see me. They see me.
Each time I had to hear him weakly say "It's my birthday..." killed me a little inside. Then finally, seeing him talking to Spidey, so confused and scared, knowing that he'll become a villain hearing it that last time. My tear ducts went into overdrive.
Just the fact that his accident and transformation happened on his birthday, of all days...
Tearjerking in hindsight, when he tells Spider-Man that he's a nobody, he really believes that because he has no one to comfort him.
The worst of it was, Spidey was getting through to him. Dillon was at heart a good person, he never wanted anything but to be treated right by others. He wasn't interested in hurting people, and Spidey had almost talked him down when Electro steps onto the power lines, flaring up with electricity, and the sniper — instructed to take a shot if he "makes a move" — interprets it as a threat and fires. That ended up truly being the straw that broke the camel's back, and Dillon had finally had enough of the mistreatment. If ever there was an example of Tragic Villain, it's right here.
To further that whole 'could have been a hero' thing, what gives Electro the strength to unlock his full powers and escape from Ravencroft is Harry telling him that 'he needs him'. Max just kinda repeats it to himself, stunned, then, obviously in pain, manages to break free by turning into electricity for the first time and blasting the guards attacking Harry, showing that even with his mental instability, he just wanted to be respected and have a friend.
The way Peter & Harry's friendship quickly falls apart, going from them happily reconnecting & joking as Peter tries to help Harry following Norman's death, to Harry killing the love of Peter's life.
Peter/Spider-Man: I don't want your money!
Harry: EVERYBODY WANTS MY MONEY!
Fridge Horror and Fridge Heartwarming ensues when you realize that pretty much everyone Harry has in his life is a hanger-on who are only interested in his money and other things he can provide for them, while Peter was the only one who didn't care that Harry was a Lonely Rich Kid and was genuinely his friend. Makes their falling-out and Harry's later villainy that much more tragic.
This may be comparatively minor, but I found Harry's interaction with Felicia kind of heart-wrenching. She seems genuinely grateful for the opportunity he gave her, and really distraught when Menken frames him for the Dillon incident. And then there was the tip about Special Projects, and calling him Harry rather than Mr. Osborn when she does so... Felicia (at the least on a professional level, and possibly at the point of infatuation) CARES about Harry, but he's too caught up in desperation and obsession to acknowledge, or maybe even sense it.
Then there's the deleted scene where she come across Goblin!Harry wrecking the building. She looks at him and says his name such a concerned yet frightened way. Then Harry looks at his new face for the first time and looks about to cry. Then just yells at her to go. She runs away like hell. While she's crying. What makes it really sad is that he just spurned the only person in the film that remotely on his side.
Aunt May. Halfway through the film she confronts Peter about his search for answers about his parents and, despite putting on a brave face, breaks down, thinking he will get himself hurt or endangered, and he is the last person she has - she even calls him her son, effectively. Sally Field sells it.
Aunt May: (sobbing) You're my boy! Mine.
Harry begging Spider-Man for his blood. It's clear he's terrified of dying like his father and just wants to live.
When Spider-Man leaves at the end of this scene Harry just curls up on the couch and cries. It is genuinely heartbreaking; this isn't a crazy supervillian, this is a kid who is scared out of his mind and really, really doesn't want to die.
The fates of Peter's parents.
There's also the recorded video log that Peter Parker's father has, explaining why he has to leave, and that as much as he loves Peter, he must leave him behind for his own good. It's also quite sad that Aunt May, and, for a time, Peter, didn't know what he was trying to do.
It's strongly implied that his father could have used the parachute to get out of the plane, but decided not to after realizing that his wife was already dead.
In a weird way, Electro being to forced to fight his own hero counts. Sure, he turned into a power hungry egomaniac, but all he ever wanted was to be noticed or be someone that people looked to for help.
Which ties into when he stumbles into Times Square and a news camera catches him. You can hear him mumble to himself, "They see me." in an awestruck way. He's not even shocked by how different he looks - he's shocked that people actually see him as a person rather than a bump on the street.
Until the camera focus on Spider-Man.
Harry teaming up with Electro starts to become this, strangely enough. His first 'I need you' is clearly said very reluctantly, something he obviously didn't want to admit. By the time the security guards have arrived, Harry is straight up genuinely begging for help. He's not lying or being manipulative; he genuinely does need Electro. His family is dead, he's been abandoned by everyone he knows, he's about to be arrested for breaking into the facility and will probably spend the rest of his life in prison for it if Electro doesn't do something pronto. The rest of his life being very short, given he's dying of a horrible incurable decease that he will have absolutely no chance to find the cure to. He's pretty close to tears by the end.
Harry: Please Max! I know what it's like to be thrown away! I NEED YOU!
In a deleted scene that seems hard to find, Peter's father appears behind him after Gwen's death and time has passed since the events. When Peter turns around to see him, he's in complete denial that this is his actual father. Andrew Garfield's performance here was probably even sadder than when he simply lost Gwen alone. Here, he's still in a lot of pain over losing the love of his life, and now a father he believes to have died has been alive the whole time and all Peter could ask him was where he had been if he had really been alive - the question all children ask about their absent parents. When he breaks down and cries in his father's arms, you can just hear how much more in pain he is now having discovered a father that only shows up now just after losing someone.