However, it seems some viewers found themselves slightly put off by one specific part of the show: all the smoking.
As the show hones in on Nilsen's 1983 arrest, we're given various clues to illustrate that we've been taken back to the early 1930s - through old cars, dodgy hair cuts and very big glasses, for instance.
But above all else we're shown just how much smoking that took place back then (yep, even in police stations), which is something many viewers watching at home have found 'a bit distracting' or simply 'unrealistic'.
One person tweeted: "Very frustrated with pretty much any pre-90's set TV drama that thinks it should show smoking in just about every scene. Des is very heavy handed in this regard. I get it, smoking was quite normal but you don't need to show it all the time. It's just odd."
Another said: "Enjoying ITV's Des but I am finding the smoking of cigarettes unrealistic. The actors are clearly all non-smokers. Compare and contrast to the expert fag-chaining in The Sweeney or the original British Law and Order."
Someone else wrote: "Watching Des on ITV. So much smoking going on. It's a bit distracting."
One other person joked that 'just watching all the smoking' was making them short of breath, while a fourth added: "I think I got bronchitis from second-hand smoking just from all the cigarettes in the first episode of #Des."
Others said they felt as though they could smell the smoke through the TV, which made them feel 'ill' or as if they needed 'to take a shower'.
However, some people argued that the depiction of smoking was more true to life in the 80s than othesr maybe realised.
One viewer who said they had lived through the era argued the atmosphere and look in the show was 'spot on', including the cigarette smoking, and another agreed: "Loving those reacting to the smoking in Des. The 80s was a fug of fag smoke, people lit up everywhere. You could buy special ashtray stands to put beside your armchair."
Nilsen, who died on 12 May 2018 aged 72, was a serial killer and necrophile who is believed to have brutally murdered at least 12 young men and boys in London between 1978 and 1983.
The Scottish killer was arrested by police after a plumber responded to the complaints made by Nilsen and other tenants about the drains at 23 Cranley Gardens on 9 February 1983. After opening the drain cover, the plumber, Michael Cattran, discovered a flesh-like substance and a number of bones.
Des follows Nilsen's arrest and the investigation that followed, with David Tennant playing our titular murderer alongside Line of Duty's Daniel Mays as Detective Chief Inspector Peter Jay and The Crown's Jason Watkins as Nilsen's biographer Brian Masters.
The third and final instalment airs on ITV at 9pm tonight.
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