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Alice Vincent: Breaking Bad has sadder, funnier and more scary lines in its script. But none are as iconic as "I am the one who knocks". Half way through the show's fourth season, possibly its best, we watch the first of many moments when Heisenberg takes over family man Walter White. His doom-inducing ego, his woeful pride, they are responsible for this ludicrous but brilliant admission. Is he the one who knocks? No, of course not. But the fact Skyler believes him is essential for the breakdown of his family, and, of course, only Heisenberg is to blame for that.

Patrick Smith: Shopping for supplies at a local lumber superstore, Walt recognises a fellow meth cooker's cart. He pauses and then offers some advice. Moments later, however, he sees his would-be rival and an associate in the car park. "Stay out of my territory," Walt growls at the men, tilting his head menacingly. They are so intimidated they get straight into their car and drive off without another word. This scene, with TV on the Radio's track DLZ building raucously in the background, is a fitting denouement to season two – Walt, it's chillingly clear, is no longer the nebbishy chemistry teacher from 17 episodes earlier.

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Chris Harvey: This scene is one of the reasons we all love Jesse. Breaking Bad's most unbearable scene is actually the one that prefigures it – the one in which Walt stands and does nothing as Jesse's girlfriend Jane chokes to death in the previous episode. Jesse buries himself in drug chaos to try to shut out her loss. But when Walt tracks him down he finds Jesse inconsolable and filled with self-hatred. "I killed her," he sobs in Walt's arms. This is the moment when Walt realises that the Jesse who flunked his chemistry class, whom he has treated as a stupid, thoughtless youth is young and vulnerable and has been damaged forever by his actions. Walt has thought only of his own feelings and he realises at this moment the full horror of what he has done. Aaron Paul and Bryan Cranston are both astonishing in this scene.

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Martin Chilton: There is a lot of humour in Breaking Bad (you need to leaven the darkness and mayhem, said creator Vince Gilligan). One great moment of this is Walt hurling the pizza on to the garage roof. But there is no dialogue in that scene. So my favourite moment of witty dialogue is when bed-bound DEA Agent Hank Schrader gets a postal delivery of stacks of new boxes of the minerals he has started to gather. He takes angry exception to his wife's dismissive description of his new prized collection as "rocks" and yells "They're minerals . . . Jesus, Marie!"

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Catherine Gee: "Say my name" is a line so good they named the episode after it. Walt negotiates a new distribution deal, but his associates – apparently unaware of who stands before them – aren't so keen on the conditions he lays out. We already know that Walt is, by now, a fully fledged criminal tough guy, but this nugget just acts as a reminder. All he has to do is tell them he was the man to murder Gus Fring then demand they tell him his own name. Suddenly on the back foot, the associate takes a gulp and utters "Heisenberg". You're goddamn right.

All five series of Breaking Bad are available to view on Netflix in the UK and Ireland.

All footage courtesy of AMC