Series Brilliant whether you've seen the film or not
I saw this series knowing nothing about the original film, so doubtless a number of things were lost on me, but I was nonetheless impressed with every aspect of it.
First, the acting is excellent. Billy Bob Thornton as Malvo is not merely an Expy of Anton Chigurh; whereas Anton was The Grim Reaper, implacable yet impersonal, Malvo is an actively malicious, trolling, Satanic Archetype trickster, allowing him to produce both genuine terror and nervous laughter in equal amounts. Martin Freeman masterfully portrays Lester, apparently a meek man who just wants to get through life, but actually a budding sociopath who remains fairly pathetic even as he escalates. As the film provides the page quote for Good Cannot Comprehend Evil, it's fitting that a lack of comprehension between people is a heavy influence throughout the series, and you come to realise that Lester is simply pretending to be the sort of person he thinks he is without truly understanding other people, allowing the various candidates for his Moral Event Horizon to be shocking and yet strangely natural. The other characters may be less interesting (in that they are pretty much ordinary people,) but are played very believably and sympathetically.
The pacing is somewhat slow, but this series makes it work, as it really lets you feel Malvo's predatory patience, Lester's continuously slipping conscience, and Molly's feelings of banging her head against a wall trying to catch them.
The best aspect of this show (particularly for a troper with all the life-ruining Genre Savvy it brings,) is the story; it is totally unpredictable. Right from the start, Death Is Dramatic is heavily averted, and the large amount of Black Comedy and Contrived Coincidences leaves you in no doubt that not only is Anyone Can Die in full effect, but it won't even be particularly dramatic if/when they do. This was the first thing work of tv, film or literature I've experienced in a long time where I truly couldn't even guess how it might end. Admittedly, there are a couple of times when Suspension of Disbelief gets pushed too far; there are a few What an Idiot moments and a Diabolus ex Machina or two, but since these are spread over several storylines all happening at once, they're forgivable, leaving it a particularly good watch for tropers.
Series Five Episodes in, Still Going Strong
I'm a few episodes now into the first season of Fargo, and it is proving to be a peculiar concept on paper. It's not a remake or a prequel or a direct sequel. I'm not confident in calling it a reboot or a spin-off either. More than anything, it is a pastiche that borrows practically every last thing from the two decade old movie of the same name, all the while trying to tell an original story that doesn't retread the same snowy ground.'
When I say it borrows everything, I mean it. The music sounds the same, the setting is (obviously) recycled, the bleak, nihilistic violence is there in spades, and it even starts with an identical bullshit claim that the whole thing is based on a true story. As for the story itself, whilst it is an original tale that is only tangentially connected to the events of the film, it is being told with almost all the same character archetypes, in a vaguely familiar situation; you've got the sympathetic yet psychopathic loser character, the folksy yet secretly genius female cop, the two incompetent hired goons - it all gets a bit uncanny.
The one new addition to the plot is a character that feels cribbed straight from another Coen Brother's film, No Country For Old Men. A mysterious stranger, "Frank", descends on the town like a malevolent trickster god, gifted with an other-worldly confidence and drive. Fargo is a setting where practically everyone is feckless or stupid in some way or other, and Frank is one of the few people who seems to have realised this is the case. As such, he has a tremendous power over everyone he meets, and is able to exert his will on the town unabated. The only person in his league is that chirpy cop. She is at a disadvantage though, because although she too knows she is surrounded by idiots, she still has a duty to work for them.
I'm only a few episodes into the first season so far, and as a pastiche, Fargo is doing a great job of capturing the dark humour, the shocking violence, and the simple humanity that assured the movie a cult following.