In Breaking Bad, Walter White's decision to quit his job as a teacher and use his chemistry knowledge to manufacture crystal meth is what kickstarts all the haywire proceedings in the series. Walt easily distinguishes himself as a talented cook, creating a monopoly in the process, but he isn't the only one that gets to manufacture the drug.
During the journey from the pilot to the finale, viewers are introduced to plenty of drug traffickers, with a total of 8 cooks among them. Some are quick-witted individuals who know their way both in the lab and in the streets. Others are only good in the lab, while some would be better off choosing a different career path altogether.
Declan's Cook
Not impressed with Todd's work, Declan, a trafficker in Phoenix Arizona, hires a new, unnamed cook. The replacement turns out to be incompetent, triggering complaints from Lydia.
Judging from Lydia's lamentations, it's obvious that Declan's cook is a novice. Lydia argues that the meth quality isn't good enough to sell in the Czech Republic. No one else considers the new cook valuable, either. When one of the smartest villains in Breaking Bad, Jack Welker, raids Declan's hidden meth lab in Arizona's desert, he chooses to kill the cook rather than take him with him as he did with Jesse. This decision shows that the cook is easily replaceable.
Todd Alquist
A career criminal, Todd is hired by Walt as his new assistant during the Vamonos Pest era after Jesse decides to quit the drug business. Walt teaches him the formula, but he never quite masters it.
Todd's inability to replicate the famous blue formula even after Walt spends weeks tutoring him shows that he is not the smartest person in the series. Todd eventually has to rely on an enslaved Jesse to cook for him towards the end of the serious.
Todd is a poor decision-maker, too. He makes misinformed decisions such as shooting Drew—in one of the most shocking desert scenes in Breaking Bad—and murdering Jesse's girlfriend Andrea, setting Jesse on a path of vengeance that ends with Todd being strangled to death.
Emilio Koyama
Emilio is a major player in New Mexico's underworld who mostly cooks for Krazy-8 and Jesse. After getting arrested and released following the DEA raid on Jesse's house, Emilio and Krazy'8 force Jesse to take them to Walt.
Less intelligent minds are easily tricked, and Emilio falls into Walt's trap easily when the chemistry teacher offers to teach them how to make his Blue Meth so that they don't kill him. Walt causes an explosion using one of the best chemical compounds in Breaking Bad and kills Emilio. As a meth cook, Emilio ought to be familiar with phosphine gas' explosive characteristics, but he isn't, and that's why he gets killed so easily.
Max Arciniega
The Los Pollos Hermanos co-founder has degrees in chemical engineering and biochemistry. Since his education was financed by Gus, he is completely loyal. It's Max who comes up with the crystal meth idea through which Gus creates his empire.
Max's chemistry knowledge cannot be put doubted. However, he makes an amateur move in the drug trade. Pushing his product into Don Eladio's territory is a decision that draws the ire of the cartel boss. It makes him feel threatened, and, by the time Max and Gus request a meeting, Don Eladio has already made up his mind to kill him. Max could have had a long and prosperous drug career, but his life gets cut short because of a maladroit mistake.
Benicio Fuentes
Benicio, the Juarez Cartel's main cook, isn't too pleased when Don Eladio brings Jesse to Mexico to teach him how to cook meth. This is because he is a highly qualified chemist with a university degree. He thus tries to make Jesse look bad.
Benicio's chemistry knowledge is good, evident from how he asks Jesse to synthesize phenylacetic acid, and Jesse has no idea what he is talking about. The meth Benicio makes isn't necessarily bad. It's only that Walt and Jesse have a slightly superior product that has caused Don Eladio to desire it. Eladio also doesn't bring Jesse to Mexico because Benicio is bad at his job. He only wants to hurt Gus Fring's business.
Jesse Pinkman
Before teaming up with Walt, Jesse goes by one of the best aliases in Breaking Bad, Cap'n Cook. He makes the Chilli P. Meth from pulverized fruit and petter. Jesse is convinced it's great, but it's actually inferior, only 50% pure. After meeting Walt, he learns a lot, and, by the end of the series when he cooks his final batch for Jack Welker, it's said to be 96% pure.
Being able to improve from 50% to 96% in under two years shows that Jesse is a quick learner. He is even to cook under pressure when using instruments he is unfamiliar with, as seen when Don Eladio demanded he is transferred to Mexico to cook for the cartel. The only problem with Jesse is that he makes so many bad decisions when he isn't in his natural lab habitat. From meeting Tuco without a plan to throwing most of his money away adn drawing the DEA's attention, Jesse won't stop shocking Walt with his decisions.
Gale Boetticher
Gus Fring's first-ever chemist has a Masters Degree in organic chemistry. He is also a specialist in X-ray crystallography. Unfortunately, Walt refuses to work with him because he trusts Jesse more.
Academics-wise, Gale is Walt's only equal, and his numerous qualifications are a confirmation of his high IQ. His promise to Gus that he'll be able to master Walt's formula after two cooks paints him as a quick learner. Gale has a mind for revolutionary concepts too, and this is perceptible from how he tries to come up with a superior coffee brew. His knowledge is vast, too, as he knows a lot about music and pop culture.
Walter "Hesienberg" White
Using his chemistry knowledge, Walt comes up with his famous Blue Meth, the best form of meth ever produced in the region. This helps him rise to be the biggest drug lord in the country.
Walt's brainpower is largely the reason why he is considered one of the greatest TV characters of all time. Rather than just cooking meth of superior quality and being part of a research that won a Nobel Prize, Walt comes up with some of his best schemes on the fly. This enables him to solve major problems such as the threat of Gus Fring and the menace that is Jack Welker. Even more impressive is that he manages to hide the fact that he is a drug manufacturer from his brother-in-law Hank, who is a very capable DEA agent.