Jack O'Connor, managing to crash the terrorists' computer systems entirely with his virus, taking out all the cameras and the V1 ending off the air. Unfortunately this happened, how shall we say? Somewhat late...
He also gets another posthumous crowning moment of awesome when his virus is reintroduced to the terrorists' systems, poleaxing them again, this happening in version 3 - more than two years after Jack's death.
Fred Hughes taking on Cody Jenson to keep the rest of his group safe, despite knowing he's outmatched.
Jeremy Torres and Lucinda Garret having a car chase across the island, complete with music blaring out their radio's as they take shots at each other. It even ends in a spectacular car crash between the two that leaves Lucinda burning as Jeremy takes his own life in defiance of the game.
Adam Dodd's fights with Cody Jenson and Jacob Starr could count, particularly since they were among Adam's biggest rivals in the game (in the second and first half respectively).
Huy Tran taking out Sam Sorenson after he attacks him and his girlfriend Anna.
Bryan Calvert dropkicking Felix Travertil off a roof, causing him to smash through the skylight of the adjoining antebuilding. Badass? Why yes, yes he is. The incident is famous enough that his handler (the real life Bryan) has a picture of himself dropkicking a tree.
Darnell Butler laying out 'Boxer' Carvalho, who was more than seven foot tall, and built like a brick wall, in what amounted to one punch. This coming after Darnell just killed three people who attacked him. Beware the Nice Ones indeed...
For reference, Darnell is a foot shorter and almost one hundred pounds lighter than Boxer.
Sean O'Cann's very Deadpan Snarker -esque sarcastic comments when cornered inside a room between two of the island's resident murderers: Gabriel Theobaldt and Dominica Sharpiro, are his Crowning Moment of Awesome.
Sean: You see why I call the guy a lunatic? * he frowns, having been called a ''young virgin metrosexual'* Hey, enough about my sex life: just concede that I have a far higher chance at getting laid than either of you and be done with it. Hell, it would be a minor miracle if Gabriel could meet any woman and spend more than a minute without disembowling her. * He looks at Dominica* And rest assured, I would come up with a suitably witty remark concerning you, however, I have no fucking clue who you are.
Character Derailment notwithstanding, the SADD vs. Blood Boy (one of the bigger villains of the first half of version 3) fight was one of the most action packed and all-around awesome moments of the third game so far. Read it here (the action starts at around page 4).
Speaking of SADD, Bobby Jacks' encounter with the group is definitely one of his best moments. Keeping his cool in the face of a giant Mexican Standoff (Bobby vs. Everyone else) Bobby manages to calm down the situation, and when things finally go to hell, both walk out of the fight completely unscathed and kill three people, granting him the distinction of being the only guy to pick a fight with SADD (the largest group in Survival of the Fittest v1-3) and come out on top. The Thread.
Ethan: "If Iím going to die, I want to be taken out by the final boss, not by some kid from the chess club. I donít want any of your circuitous bullshit about a classmate killing me. In the end, itís you. If you hadnít done this to us, they wouldnít be killing. Even if they kill, itís still you in the end. I donít want you to be able to hide behind a scared kid. I want my blood on YOUR hands. I deserve to be killed by you."
Not to be outdone, his partner Feo Smith gets the rest of the escape group together and manages to send a message out to STAR, and when the area is turned into a dangerzone by the terrorists stays behind to destroy evidence of their work while urging the group to run. Because of this she doesn't make it out.
Eve Walker-Luther also earned one at the hands of Sarah Atwell. This is when she's being tortured.
No matter how you feel about the mechanics behind it, let's face it; Liz Polanski deactivating her collar using melted aluminum is freaking awesome. To get an idea, it incited a Mass "Oh, Crap!" from the terrorists. Even with what comes after (Danya randomly killing characters and later sending a death squad to the island for both this and her destroying cameras afterwards) it still has that punch.
Harry Hanley was one of a slew of characters to get inactive killed following the V5 crash. How does he get to go out? By taking out then-top killer Max Sawyer and another murderer in a Dying Moment of Awesome. Not bad for a character with less than ten posts total.
Sawyer wasn't exactly a slouch himself, coming off killing three people in the space of about five minutes and having it in him to take out both his ambushers before he finally keeled over.
Hansel Williams's fight with the man who had inadvertently set him on his path to becoming the most prolific killer in V5, Theodore Fletcher. What ensues is a brutal back and forth before Hansel takes out Theo's eyes and smashes his head to pieces with a pipe wrench.
His later fight with his rival from school, Garret Wilde. Garret had become a player hunter at this point, having taken the life of Jaquilyn Locke earlier. After a brutal fight between the two that callbacks to their pregame together and Garret seeming to be on the cusp of killing him, Andi Victorino comes in for the save.
His last fight before entering endgame is with Katarina Konipaski, the other highest killer and fresh off her fight with Matt Vartoogian.
Cass Prince just witnessed the death of Travis Lynch, who kept them company since they first woke up on the island, and is now faced with an utterly remorseless Jerry Fury and his accomplice, who both threaten Cass to give up Trav's belongings or get killed also. They Take a Third Option by punching Jerry right in the face and running off with the supplies, taking a minor injury but otherwise getting away free.
Kaitlyn Greene decides to play a deadly game within a Deadly Game when her friend Alba Reyes stumbles into the cove to find her. Kaitlyn coerces Alba into trading weapons with her before forcing Alba into a standoff/game of chicken with her while high tide threatens to flood the cove that they are in. What follows is an incredibly tense scene as Alba tries to talk sense into Kaitlyn and Kaitlyn pushes on, the rush of danger and a misguided attempt at coaching Alba into being stronger keeping her going, eventually ending in Alba finding the fortitude to "win" Kaitlyn's game like she wanted her to.