Ashlie and her husband are in the midst of a 2,549-mile drive from Pittsburgh to their long-awaited honeymoon in California. "We both agreed, though," she tells me, "that we have to stop off in Albuquerque for some meth." She is wearing a T-shirt that shouts "Yo Bitch!", and waving her little bag of blue crystals as though they were nothing but novelty sweets.

Her husband, also holding a bag, is trying on a familiar-looking black hat – $39.99 – and posing moodily for pictures. "I'm totally Heisenberg!" he says, laughing. Their dealer, the legendary Candy Lady, just looks on and smiles.

This is a mere snapshot of a tourism industry constructed around Breaking Bad: the AMC drama phenomenon in which mild-mannered chemistry teacher Walter White (Bryan Cranston)turns his expertise to producing crystal meth after a cancer diagnosis leaves him fearing for the financial future of his family.

While not airing in the UK, it has translated – via Netflix (new episodes will be available in the UK every Monday from 12 August), DVDs and the online underworld – into one of the most engrossingly layered character studies ever put to screen, with Walt's five-season arc charting his fall from likable antihero into the monstrous depths of his villainous alter-ego, Heisenberg. Its writing is masterful, its performances are iconic and its setting of Albuquerque, New Mexico, has become a character in its own right – even if, understandably, the city didn't like to acknowledge it.

"At first we thought it made us look grim and would put people off," explains Natalie Kohl, a representative of the local tourist board. "I mean, you know, it was still a show about drugs."

You can see her point, although the subject matter doesn't consciously define the city as it did with, say, The Wire's depiction of Baltimore as a city riddled with crack. If anything, the setting is complimentary, with creator Vince Gilligan picking Albuquerque over the original setting of California purely because of its striking sense of depth.

It's a city that feels, at once, intimidatingly grand and comfortingly communal, where small towns find themselves neighbouring seas of desert and the looming shadows of mountainous teeth. As the show gradually eased into popularity, around season three, the city started coming around to the idea of being associated not with "a show about drugs", but with a critically acclaimed, Emmy-winning work of art. "We thought," Kohl says, "that this was something we could get on board with."

And so, here we are. It's a pristine Saturday in May – hot, but not oppressively so – and I'm waiting for the flagship of Breaking Bad's tourism industry: ABQ Trolley's BaD Tour. Over three hours long and taking in 13 locations over 38 miles, the tour was set up last July by Mike and Jesse (coincidentally the names of two of the show's characters), who have been giving open-air trolley tours of the city for the past four years. As Breaking Bad's final season approaches, however, this has been the most successful one yet: they routine sell all 34 seats per tour within minutes of online reservations opening.

The trolley departs from the plaza of Historic Old Town: a quaint little district that offers souvenirs (including Breaking Bad aprons), a museum of natural history and a Christmas shop.The trolley starts to trundle and Crystal Blue Persuasion by Tommy James & the Shondells – soundtrack to a fantastic montage in series five – begins to play. Mike and Jesse are excited, and it's infectious.

The pair are friendly, insightful hosts. Jesse drives while Mike, whose previous job involved sorting permits for the show's shoots, explains how Breaking Bad has led to tax cuts of 30% for productions filming in New Mexico – making it, in his opinion, an attraction now stronger than the city's annual air balloon fiesta. As we pull up at our first stop, the house belonging to Jesse Pinkman, Walt's charismatic partner in crime, a relevant clip from the show plays on a screen overhead. Mike regales us with trivia, about how the guy who owned the house sold it after the first season, which meant they had to construct interior sets for season two.

On 16th Street, in a bright, affluent part of town, Jesse's house is just that: a house. So why is it so bloody exciting? This inane giddiness at everyday buildings is a common theme throughout the tour. From Jesse's house we move on to locations such as the hideout of season one's Tuco Salamanca, the offices of crooked lawyer Saul Goodman (now a bar called Hooligans), the Octopus car wash that Walt moonlights for in episode one, an eventful street corner, a Denny's that featured once …

All of which are, when you take a step back, too laughably banal to "ooh", "aah" and take pictures of. But that, it becomes clear, is the power of this show: its themes, characters and story are as immersive as a great novel. And if, as artist Grayson Perry said earlier this year, television is now our literature, the tour is like a walk around the pages of your favourite book.

This is no more true than when we the pull into one of the two major highlights: Los Pollos Hermanos, the fried chicken chain owned by season two's infamous drug lord Gus Fring. In reality, it's a burger joint called Twisters, which, much like everywhere in New Mexico, serves its food with either red or green chillies.

The interior declares proudly: "Yes! Breaking Bad was filmed at Twisters!" and even has a guest book for tourists to sign. The teenagers behind the counter look at us with withering contempt, an expression that also flashes across Mike and Jesse's faces as another tour group enters. "One more stop," Jesse says, regarding them frostily. "The White house."

According to Gillian's pilot script, "no president ever slept there", but you'd disagree if you had heard the gasps. Walter White's house is right there. Mike plays us a clip from season three, in which Walt, enraged, manages to throw a gigantic pizza on to the garage roof.

"Apparently," he laughs, "the guy who owns the place goes out to pick up his paper some days, and has to remove a giant pizza a fan has thrown up there."

But given that the owners, according to local lore, have made up to $500,000 from filming fees, they can probably live with it. "He even comes out and says hello sometimes," says Jesse.

The tour finishes there, which gives me a chance to ask Jesse about that rival tour group. I'd thought these guys were the only ones.

"The Candy Lady," Jesse replies. "She sent an employee on our tour once and then, a few weeks later, they had one. Pretty convenient."

Debbie Ball, aka the Candy Lady, is what the Albuquerque tourist board has come to call "a character". Her sweet shop, on Old Town's Romero Road, rose to local notoriety in the 1980s when she started selling erotic confectionery.

Since then, though, her most famous product has been "meth" in little "drug dealer" bags that were used as props in the first two seasons. She now sells them for a dollar each, shifting more than 25,000 in less than a year. Breaking Bad fans, she tells us, account for 20% of her income: "We really didn't think it was going to take off like it did. At least now I can say that we sell sex and drugs."

Her business exists on a fringe of the industry that critics see as cynically glamourising crystal meth, a drug that, while relatively little-known in the UK, has been called the US's number one drugs menace by police.

That makes hers a truly bizarre trade – like going on a Trainspotting tour of Edinburgh to pick up a few novelty syringes. Debbie, though, maintains that fans are merely celebrating the show.

"They don't see it as a drug – they see it as a prop," she says, before assuring me that the sweets are never, ever sold to children.

This defence is also used by Keith and Andre West-Harrison, whose spa, Great Face & Body, also offers Bathing Bad, a line of blue bath salts in 8oz plastic bags. "We've had one negative email," says Keith, "telling us that if we knew what crystal meth did to families we wouldn't do what we do. But real meth isn't even blue. I know what meth looks like, and that's not it."

Like the Candy Lady, they have been very successful. A year ago the pair set up a Facebook page for Bathing Bad, and the next day they sold 12 bags before they even had a recipe. Now they make 50lb of it at a time and run classes in which visitors can "cook" the meth with them.

It is, thanks to the duo's charisma, stupidly fun, but it's also conflictingly crass. Should I be doing this? Should I be larking about with what, if it was actual methamphetamine, would have a street value of $1.3m? Is this whole thing, overall, a big ol' sinister cash-in or just a harmless bit of tourism?

That, it would appear, depends not only on your own sensibilities, but how chatty you feel like being when bringing your faux-meth back through customs. One thing's for sure: much like Breaking Bad itself, Albuquerque is certainly not boring.

• The BaD Tour (abqtrolley.com) costs $65pp and leaves from Historic Old Town every Sunday. More information from Albuquerque tourist board's Breaking Bad site: itsatrip.org/breakingbad.• Flights to Albuquerque and all tours were provided by AMC in promotion of Breaking Bad seasons 1–5 on Blu-ray and DVD – both out now. Top 10 places to stay in Albuquerque. American Airlines and United fly to Albuquerque from Heathrow via Dallas and Washington DC respectively. The BaD Tour costs $65 and is booking for its August-September tours (leaving from Historic Old Town every Sunday). Other websites include Bathing Bad's and the Flights to Albuquerque and all tours were provided by AMC (amctv.com). Breaking Bad seasons 1-5 are out now on Blu-ray and DVD; new episodes will be available on Netflix from 12 August. For places to stay in Albuquerque, see theguardian.com/travel/new-mexico. American Airlines and United (united.com) fly to Albuquerque from Heathrow via Dallas and Washington DC respectively from £542 return