The dev chase sequence, particularly when Mouser activates 'God Mode', allowing him to recreate the local environment to his requirements in order to catch up to Guy.
The montage of Guy climbing through the ranks without killing anyone. His rapid levelling makes his mission go viral, as streamers and players discover you get levels faster by playing good, rather than bad.
Hell, the entire IRL montage as people talk about the rogue player "Blue Shirt Guy (BSG)".
Bombshell's "awakening". After Guy takes out the player character she's with, he encourages her to stop hanging around douchebags. He suggests dating somebody nicer, but she decides she doesn't need any man at all, and marches out to find her own way. According to Keys, she then writes a very good feminist manifesto, implying she learned and grew a lot in a very brief time.
The stash house fight with a newly-level-100 Guy saving Millie from being overwhelmed by respawning enemies, only to be subverted even as he casually ditches his motorcycle and doffs his helmet saying "Was that cool? It felt really cool." They proceed to kick ass, with Guy at one point summoning Mega Man's Mega Buster as a weapon.
Millie kisses Guy to get his memory back. Remember, there isn't a button for that.
Awesome that first Guy found the button, then Millie did too.
The non-player characters banding together to mount a total walkout, with some encouragement from Guy and Millie.
Guy's fight with Dude looks like it is going to be a Curb-Stomp Battle in Dude's favour, until Guy gets his shades back and summons Captain America's shield (much to the surprise of Chris Evans), complete with appropriate fanfare, which utterly stops Dude's deathblow in its tracks.
He follows this up with a Hulk-infused uppercut, and then draws a lightsaber, which apparently shocks even the devs!
He continues his armory showcase with two Valve shout-outs, using the gravity gun to slam Dude through an awning, then pulling a portal gun to close the distance, although Dude counters by darting through the portal and aiming to break Guy's ribs.
The finale to the fight? Guy has no weapons that can beat Dude, because the devs gave him God Mode. He uses his shades as a weapon the devs can't block, putting them on Dude to show him the game world, fundamentally altering his code by putting him on the path to sentience, and also completely distracting the simpleminded NPC.
Antwan getting his comeuppance, with him losing most of his fanbase to Free Life instead of his buggy rushed sequel Free City 2; with the added bonus of Soonami losing a ton of credibility following the whole BSG incident.
The ending is a mix of this with Heartwarming Moments. Guy pointing out to Millie that he is just a program and that someone wrote him as a love letter attests to how much Guy has advanced beyond his original programming. He's thinking all the way out of the box, perceiving his creator and his own purpose all by himself, making him very much like a human.
