Television law dictates that bad people either turn good or get their comeuppance. Real life doesn't always work that way. In real life, bad people keep the money you paid for a timeshare that doesn't exist. They overcharge your granny for retiling her roof. They enjoy watching the Pingu DVD they nicked from under your niece's Christmas tree (the one in which Pingu steals some sweets, gets grounded and learns his lesson).

In that sense, Breaking Bad is like real life. Bad people do bad things and get away with it. Bad things like drug dealing, kidnapping and murder. Things for which Pingu would have been grounded until he was a very old penguin indeed. It begins with gifted chemistry teacher Walter White (Bryan Cranston) discovering he has lung cancer. He uses his scientific know-how to make the purest crystal meth on the streets, with the help of former pupil and small-time drug pusher Jesse Pinkman (Aaron Paul), as a way of catering for his family's financial needs long after his imminent death. This previously strait-laced suburban father finds that drug manufacturing is everything that teaching in an Albuquerque comprehensive isn't. Dangerous. Exciting. Fewer awkward staff parties.

Jesse, meanwhile, becomes the show's unlikely hero. He's a junkie, thief and pusher, mostly trying to do the right thing, though thanks to his Laurel & Hardy relationship with "Mr White" he is continually dragged back into the mire.

So how would Aaron Paul feel if, in 20 years time, a daughter he doesn't yet have brought Jesse home?

"I'd like him," he says, then hesitates. "Y'know, that's not true. He's a murderer, a drug dealer, a drug manufacturer and a drug user. That's not a good combination to be going out with my daughter."

But he's a good boyfriend, I argue.

Paul laughs. "He is a good boyfriend! Absolutely. He just needs to get his shit together before he starts hanging out with my daughter."

'If you use meth for two years, it ages you 20 years. It's crazy what it does to you. It's a horrible, horrible drug'

Aaron Paul and Bryan Cranston in Breaking Bad. Photograph: Frank Ockenfels/AMC

Among Breaking Bad's many star-making turns, not least Bryan Cranston's unpredictable leap from Homer Simpson made flesh in Malcolm In The Middle to terrifying gangland kingpin, Paul's is the biggest. You will root for his scoundrel, feel his pain when he's forced to blow a semi-innocent party's brains all over the wall. He's a classic Lost Boy with an outsider drawl that almost a carbon copy of Christian Slater's in True Romance. A moral compass struggling with his own moral compass.

"It's crazy [that people side with Jesse]," he says. "At the beginning, everyone – including me – saw him as just a drug burn-out. A kid with no sorta brains. But as each episode was revealed to everybody, it showed quite the opposite. It's incredible how Walt and Jesse are completely trading positions. Walt has no morals whatsoever any more, and Jesse, who wants to try to be good, is terrified of him."

Last month, Paul walked off with his second Emmy for Best Supporting Actor In A Drama, crowning a year in which Breaking Bad took firm root in the British psyche. Broadcast on AMC in America, it hasn't found a stable home on our screens yet, beyond graveyard screenings for the first two seasons on FX and 5USA. The many contractual complexities of transatlantic show-swapping are beyond mere mortals, but you'd hope, given the level of interest, that situation might be rectified soon.

Meanwhile, a show built around the deadly supply and demand of an addicted clientele has become an addiction in itself. Unwilling to wait for a UK TV channel to buy the rights, fans have flocked to streaming sites such as Netflix, which cruelly only gives you 15 seconds to switch off once an episode has finished before it boils up a teaspoon of the next one.

The action is slow and sporadic. It might focus one week on Walt trying to hold his crumbling family together, or Jesse trying to kick his habit. It's content to lollop where other shows run. Then it explodes in gruesome violence and bravura set pieces, served up with the bombast and humour you just don't get from a Wire grumblethon.

With series four out on DVD, and five (the first half of which just aired in the US) set to be the last, there is just one hit remaining. It will mean the end of a brilliant part for Paul. Seldom will a role be so rich that it facilitates him pretending to be high, pretending to kill someone and pretending to be heartbroken, all in one episode.

So which is the most difficult? "Oh God. Probably killing a man. I've never killed a man before," he says. "But I've definitely been heartbroken. And … I can imagine what it's like being super high. I do so much research on YouTube. It's where the most honest stuff is."

How do you go method for meth addicition?

"I talked to a lot of addicts, people that are now clean. Meth is such a dark monster. It takes control of you. I lost someone very close to me to meth. She's sober now, but we don't talk any more. I saw meth take complete control of her. It was so quick. When someone uses meth it ages you 10 years in a year. If you use it for two, it ages you 20 years. It's crazy what it does to you. It's a horrible, horrible drug."

'In the street, I get a lot of "Yo, bitches!". A lot of people ask if I can hook them up with some blue'

Aaron Paul and Bryan Cranston in Breaking Bad.

Inevitably, Jesse's endearing attempts to act the streetwise tough have made him Breaking Bad's cult hero. "In the street, I get a lot of 'Yo, bitches!'" confirms Paul. "A lot of people ask if I can hook them up with some blue. It's funny: I don't have young girls running up to me screaming and crying, I have grown men running up to me screaming and crying. I love it, though. Breaking Bad turns our fans into fan-girls when they meet their favourite character."

Presumably, he also has to deal with people assuming he and Jesse are one and the same.

"Yeah, it's funny. Actually, it's not funny," he admits. "It's sad if people assume that, because I play a druggie on TV, I'm a druggie for real. I'm quite the opposite. Drugs, I'd like to reiterate, are bad. Don't do drugs and don't kill people! It's obvious, but worth remembering."

This must be a strange position for an actor whose early ambition was to be in Fraggle Rock.

"Yes!" he enthuses. "Fraggle Rock was my first memory of a show I watched all the time. That, and Duck Tales. Remember how Scrooge McDuck used to dive into a pool of his coins? I wondered how he didn't hurt himself. That never made sense to me."

He seemed to be having a good time, I suggest.

"He was having a good time. He's the world's richest duck." Maybe, somewhere in a basement in LA, a swimming pool of Emmys has begun.

Series five of Breaking Bad begins on Netflix on 1 Nov. Series one to four are on DVD now

JESSE'S WARES

How drug dealer Jesse Pinkman became Breaking Bad's most sympathetic character. (Includes faint series one and two spoilers)

Brotherly love

For a minute, black sheep Jesse is welcomed back in the bosom of his strait-laced family. But then his parents discover a joint belonging to his golden-boy brother. Jesse takes the hit, and he's back out on his ear.

Stuttering seduction

For all his front, Jesse is rubbish at the love game. The best chat-up line he can muster, to clearly interested neighbour Jane, is, "I've got this kick-ass new flatscreen … Wanna see?" And even then she has to make the first move.

Free nibbles

"No bong, no beer, no weed." Jesse tries to make serious street hustlers out of his motley crew of feckless associates by inviting them to a pep talk, complete with complimentary pretzels and supermarket cola.

Peekaboo

Jesse is forced to whack a couple of junkies who've robbed Skinny Pete, but he ends up playing peekaboo and buying Twinkies for their neglected kid.

Jesse the literary critic

Jesse tries to show off in front of his burned-out dealer friends with a fancy phrase that he's learned from his group therapy tutor. "This situation is messed up – totally Kafkaesque," he exclaims, nodding sagely to his impressed crew, still not entirely sure what he's just said.