Maxxie grabs the gun from the crazy Russian, turning the tables.
Sid grounding his own father after his mother leaves. Then Sid's Series 2 episode gives one to Sid's father when he curses off his own Jerkass father and kicks him out of their house.
The perfect order he left behind before dying: breaking free of his father's emotional abuse, setting his son free from the same, insisting he has never disappointed him, getting his wife back, and even solving Sid's relationship problem with an advice. Then sitting down in the armchair with a glass of whiskey, and falling asleep peacefully.
Tony gets his groove back at the end of his episode in season 2, confronting Sid and Michelle.
All of that episode, more or less, but the moment it happens is when he grabs the guidance counselor by the throat and makes it very clear that he knows exactly what "animus" means.
"It means spirit, courage, passion, wrath. This is mine."
"Fuck it, for Chris." And the fireworks at his funeral!
Thomas comprehensively besting Johnny White in the chilli eating contest.
"I'm Katie fucking Fitch! Who the fuck are you?"
The entirety of J.J's season 3 episode.
And basically everything J.J does from then on.
Special mention goes to JJ in season 3's finale. From telling Freddie off, to winning the race, to disciplining Freddie, Cook and Effy into solving their Love Triangle, to taking the command after Cook Senior is cnocked out and steering the boat away from the town. More than a few female viewers had to wonder why it wasn't him that Effy chose.
Naomi sacrificing the election (which had been rigged in her favour) to prove that while anybody can say they hate injustice, she actually means it. "No need to pad your bra!"
Emily gets two. The first, when she storms back into Naomi's room and tells Naomi to stop being such a prick and treat her like a human being; and the second, at the end of the twin fight at the Love Ball when she somehow resists the temptation to lay the final punch into Katie (which, in turn, is the cue for five minutes of solid Heartwarming Moment).
"I'M COOK!" Two different characters say it, on three different occasions, and it's a CMoA Every. Single. Time. (When Cook's dad escapes the mob, when Cook in turn avenges his dad's decades of neglect, and when he takes on John Foster.)
In the final episode of Series 3, J.J., who is usually portrayed as a shy autistic boy, suddenly puts all of the characters in their place, resolves the situation, wins the steeplechase, and steals a boat to boot.
Franky Fitzgerald got one in her very first episode: when she turns up to Mini's party and just as Mini is about to insult her, rattles off a string of insults people at Oxford made to her first. Something that also should get honorable mention is the spectacular way she evades the bullies at the very beginning of the episode.
In S6 Liv confronting Rich while he is studying about how he isn't still mourning Grace is one of these.