In Doubt Academy 1, Roxy taking control of the sixth trial. Considering her general crybaby response to everything prior to this, it's pretty awesome to see her suddenly commanding attention and leading the trial.
She even manages to manipulate Monobear into allowing the ghosts to communicate during the trial.
Doubt Academy 2
In Doubt Academy Black, Takara gets an awesome moment in the first trial, because when he insisted that he knew who the culprit was, he was right!
This is an unusual post-mortem example, since it takes place in the "dead students blog" of Doubt Academy Black, but Iko manages to resurrect the "glitches" of Angelo and Daiki into their real forms.
The fact that in both Black and White, the students win, successfully catching the Mastermind. And as even Doubt Academy's administrators noted, this is even more of an accomplishment because the Mastermind's name is in the killer randomization box three times, and thus has three times a chance to be executed as any of the others. So it's quite a feat that both killers were ultimately caught and executed for being the Mastermind, and not merely for being culprits.
This is an unusual post-mortem example, since it takes place in the "dead students blog" of Doubt Academy White, but Takahiro finally gets fed up with Mimi's "prideful bullshit" and, to paraphrase, tells her to shut up because now that she's dead she's no more important than anyone else, including all the people she's unnecessarily insulting.
A meta-example: Chris Peril was a last-minute addition to the Doubt Academy White roleplay (the spot was originally taken by a SHSL Deep-Sea Diver), but he's one of the survivors. He was a last-minute replacement, but he survived the whole game without being killed or executed.
Doubt Academy 3
In Doubt Academy Alpha, the chapter 1 "motive" is a card belonging to each student with a reason why Monobear thinks they suck. However, a lot of the students (except obviously for whoever the culprit turns out to be) pull Shut Up, Hannibal! moments in their minds: Saori is not just a pretty face and has years of practice to justify her talent; Shay's talent is not a fluke and even if it was, Shay could just do something else; Ayako is not in danger of having her talent taken away from her since she already has no access to her laptop in Ouranos/Gaia, etc.
In Doubt Academy Alpha, Yuuto asks so many useful questions while investigating chapter 1's murder that Monobear gets sick of his face and even asks if Yuuto's trying to earn "protagonist points", because in a sort of "worthy enemy" moment Monobear thinks Yuuto asked the most questions, which is precisely why Monobear finds Yuuto so irritating!
Yuuto also gets an unusual retroactive one that unfortunately comes too late—recently, Emiko has confessed to Kosuke that she was the one who killed Ayako...which means Yuuto actually accused the correct person during chapter 1's trial! But this has come too late, since Yuuto was the victim of a mistrial and wrongfully executed.
In Doubt Academy Omega, Alphonse gets one when he puts himself at risk to discover more about chapter 1's crime, by putting his hands in the blister-causing ink that was used to kill Daisuke before the culprit made it look like Daisuke drowned.
In Doubt Academy Omega, Naoki gets one when it's his plan that exposes the chapter 1 culprit, since Naoki came up with the idea to get the still-wet Alphonse to wash off Lee's tattoo, which exposes her incriminating bruises.
Your mileage may vary on how much this qualifies as "awesome", but in Doubt Academy Omega, the first culprit, unlike most culprits, doesn't bother justifying herself when she's finally proven to be guilty. She tells the others to not blame themselves, because she does deserve her upcoming execution. And then she turns to Monobear and actually asks him to start her execution!
In Doubt Academy Omega, Gorou gets one when he intervenes and stops a fight between Rune and Aqua in chapter 2 by suplexing Aqua!
Naori gets one in Alpha when her last-minute exercise plan exposes the chapter 2 culprit.
Mitsu gets one as well, since Naori was able to come up with that plan because Mitsu found the evidence proving "the culprit was hurt", so Naori's plan could expose the culprit's injury and cause the culprit to give himself away.
Gorou gets one in Omega when in chapter 2's trial, he presents multiple pieces of decisive evidence pointing to Usoko's guilt, and even though Akira confesses to protect Usoko, Monobear confirms that the culprit really was Usoko, so Gorou catches chapter 2's true culprit.
After the conclusion of the third trial in Alpha, a rescue party immediately gathers and descends into the Labyrinth, which has just had multiple bombs go off, on the slim chance that Nanoka is still alive. Of those involved, only Kozure and Naori have even been in the Labyrinth with any regularity — Dante, Saori, and Shay have little to no experience with mining. The result of their efforts? They find Nanoka pinned under the rocks, horribly injured, but alive, and successfully get her out of there.
It can't be said enough how unprepared most of the group was for the sudden and urgent mining expedition. Many of them are suggested to be physically weak, Shay is clearly terrified of the Labyrinth (and yet is the one who called for action and started off the rescue), Dante isn't much calmer and actually comes close to panicking and killing Nanoka when she grabs him, and Saori shows up in a kimono and has trouble keeping up. In the end, though, they all pulled through.
Chapter 5 in Omega ends with a completely accidental moment of awesome when most of the class, who can't properly figure out who killed Akira, end up split between voting for Akira himself or Nicanor, the most popular suspect. The resulting tie leads to the dead students' votes, which are supposed to act as a tie-breaker, being counted... but this leads to yet another tie. Finally, an exasperated Monobear just decides that since Akira killed Shinji, the students technically did find a murderer and lets them go without an execution. However, this does have the significantly less-awesome effect of making whoever killed Akira into a Karma Houdini.
After the Omega and Alpha classes are finally united in the Elysium facility, many of them get to sharing their stories and mutual grief. When Minako realizes that all of the flower crowns she dutifully made for each student don't technically exist any more, she begins to break down- and Chiemi, reflecting on her parallel experiences, does so too. The moment of awesome comes when she points out Shun, mentioning 'not even the boy with us was here for me'- and that's all it takes to give Shun a sudden, massive Heel Realization. He finally admits that he's caused a lot more harm than good, and as hard as it is for him to be good, he wants to try and become the person others think he can be.
When the morgue becomes available for investigation, the students find the bodies of all of their previously murdered and executed classmates there. Imogen, due to her medical background, takes it upon herself to give all of the dead students some dignity, and spends time stitching together the bodies of those who had been decapitated, dismembered or otherwise cut up; all of them, by herself.
In Chapter 9, the murder ends up particularly complex, with three murders occurring in a single night. Though the group has to be split up to even investigate the bodies properly, in the trial they manage to pinpoint at least one culprit: Chie Narita, who turns out to be the ONLY culprit at all; as Monobear reveals after the votes are tallied, both Aome Takahara and Eva Valencia actually killed themselves. The fact that the group managed NOT to mistrial is pretty awesome in itself.
The ending. Despite the arguing that results in the survivors splitting into two groups, they end up working together to not only secure an escape route, but to clone the dead students. It's a long plan that involves three months of constant preparation, with fears that the Collective might interfere at any time, but ultimately it pans out and ends with every student of the 91st Class walking out of Gaia alive. Highlights include:
Chiemi, Kosuke, Rune all standing up to Yasuda when he tries to sabotage their attempts to clone the dead. They're all prepared to use physical force to stop him, and Momoko and Shay actually carry out those threats, incapacitating Yasuda and allowing the others to put him back in the jail for another three months. Given his Karma Houdini status from the past two rounds, it's great to finally see the students putting him in his place.
Takeshi running the cloning technology almost entirely on his own; three of the students act as his assistants and the other four work on kitchen and guard duty, but Takeshi is the only one still alive who truly understands how the cloning process works and thus carries the burden of overseeing it all, lest an error be made and cause weeks or months of delays. He even chooses to revive those who caused the killings in the first place, even though they murdered five of his coworkers.
The survivors who tried to leave going back to help those who stayed. While part of this was out of necessity — Takeshi was the only person who could get them past the Collective checkpoints — they do what they can to help even in spite of their hesitance over the ethical implications of cloning. Special kudos to Gorou, Hikaru, and Naori, who are part of the recon team that takes down the armed Collective guards to clear a safe escape route for everyone, putting themselves in physical danger to help the others.
Doubt Academy 4
In Rot's third chapter, Hibiki's execution. Not for the execution itself, but the fact that it happened entirely on her terms. She didn't seem remorseful for Rover's death, she faced it with a smile, kept performing right until the end and didn't give in to fear or despair at any time during it.
A powerful one in Chapter 8 of both Rot and Rubble: Both games successfully identify their Masterminds; Rot even happens to be on their first Mastermind vote, making them the first Doubt Academy game to take only one attempt! It's also the earliest Mastermind vote success that any of the 26+ student rosters have had, compared to White getting it in Chapter 9 and Black and Epsilon getting it in Chapter 10. As a result, DA4 in general has the highest survival rate of any of the rounds (counting the pending culprit and Mastermind executions, and not counting the mass revival in DA3), with nearly 40% of the students surviving! Including the two people critically injured halfway through the game, and the two people ressurrected as part of Chapter 7's supermotive!
The biggest Wham Line in Rot, coming from a person who had been Beneath Suspicion for the case they're referring to. For context, Sully is admitting to having killed both Aya and PK, the latter of whom's death had remained a mystery with little hope of resolution since the case ended.
Sully: God, guys I just wanted to go home. And yes, other people have families, Maeno, but are they doing anything about it?
Sully: Asano was right, youre wrong.
Sully: Ill save you all the air of mystery.
Sully: Im two kills ahead of all of you.
Related to this, Misaki Asano is the one who managed to almost singlehandedly figure this case out after the fact, with a little help from PK herself.
Doubt Academy 5
Doubt Academy 6
In Tora's first chapter, the reaction of many students to being ordered to kill Takeshi is to either panic and not be sure what to do (without being willing to murder Takeshi)or to quietly resign themselves to what's going on. Holly's immediate response to hearing the news is to grab Takeshi by the arm and hide him in another building until she can get her bearings, and from then until his death she tries her best to keep him safe and away from the others.
Tora's nightwatch. Yuka's idea, and even when she says she isn't going to be involved that week, she's involved every time. The evidence gained from them have saved their class from a handful of mistrials.
After the merge, many people take part in nightwatch or patrols, and willingly volunteer to do so even though it's a lot more dangerous than just sitting in your room during motive times.
In the event following the merge there were a few of these, such as every single person voting 'ally' in the first segment (meaning no one chose to betray)
Michiko and Holly trying to perform CPR on Mamimi in chapter 2, even though it obviously wasn't going to work.
Chapter 4 of Parelthon has Haruna setting up ink traps all over to try to incriminate the culprit who would inevitably kill someone. It doesn't quite work, but it was still a pretty clever idea.
In Chapter 4 of Tora and Chapter 6 of Telos, Akio and Ailani are revealed to be robots. Their reveals are pretty cool too - the former turns out to have been storing the murder weapon inside his own chestplate.
The way that Ailani is outed is especially badass: Haruna, taking suggestion from another classmate, dumps a bottle of wine on her, revealing her true nature.
Ryouji abruptly being brought back to life, which immediately catapults Chapter 6 into being the biggest Wham Episode so far. Doubly so when he turns out to be the murderer that week, and is executed once again.
Chapters 5 and 6, the cases immediately following the merge, are two of the most outlandish and ridiculous so far...and also the most impressive.
The victim for chapter 5 dies in front of several witnesses, having been pushed out of a window on a high-up floor of the hotel. The culprit's attempts to frame others and get away with it are more and more bizarre as more clues are brought to light, and for much of the trial, no one is really sure who to suspect, as even the three people who could fit the role have alibis or evidence proving they didn't do it. That is, until characters start pointing out a certain someone is not beyond suspicion simply because people are fond of them and they're kind and seemingly harmless. This culminates in drawings of minions and garfields being used as evidence, the revelation that the culprit hid on top of the elevator to follow their target, tracked said target while wearing an enormous, cumbersome Piney costume, and managed to sneak past no less than three people on nightwatch without being seen ONCE.
Genta, Yuka, and Michiko all deserve their own honorable mention in this case. The former for being the murder victim and surviving for an incredibly long time under bad circumstances, to the point where his determination to live is directly referenced several times in the narration and dialogue of the characters. It took his body being literally shattered for him to finally die. The latter two for being the most emotionally compromised by the case (Yuka was very close to [[spoiler: Genta and watched him die in front of her while there was nothing she could do, and Michiko similarly was trying to save his life when she was ambushed and threatened herself - and had to watch as he was pushed out of her window to his death) and still contributing a lot to the trials and managing to hold themselves together enough to bring the victim's killer to justice.
Chapter 6's trial is an action-packed calamity. Ailani is revealed to be a robot because Haruna dumped wine on her; Ebull and Ai both physically attack the culprit after they confess, Michiko and Yuka show exactly how good of a team they are, Ailani draws several KNIVES on the culprit and threatens everyone to be quiet, Piney reveals his real self at last, and the Ateitis class reveals that they know who their mastermind is (or at least, are almost entirely certain of it). It's also revealed that the masterminds did not expect or want the mutual killing to happen, and that they work for a higher power. Lastly, it's finally confirmed that the characters are in a virtual reality.
At the very end of Chapter 6, Andrew shoots a nail gun at Monobear, several times, embedding them in his forehead right between his eyes. The aftermath of this isn't pretty, but the action itself was pretty damn awesome.