I was already a Terry Pratchett fan and a Neil Gaiman fan in 1990, when their comedic novel Good Omens showed up in the bookstore I worked at, and I dibsed it, took it home over the weekend, read it in huge gulps, and wrote an enthusiastic review on a 3x5 card that I tacked to the bookshelf next to it on the new release rack at the front of the store; I hand-sold hundreds of copies, and have read it dozens of times since.
It's really a perfect gem of a novel, combining so much of what makes each of those authors so great: Gaiman's ability of tap into the deep roots of myth and to spin the most wonderful of phrases; Pratchett's incredible heart that can turn sweetness up to 11 without introducing so much as a drop of sentimentality, his Douglas Adams-style gift for surprise jokes that are so well-turned that they elicit surprised barks of laughter when they occur.
I've been very excited and optimistic about the Amazon Prime adaptation of the novel; I knew Gaiman had put everything into it, and had taken instruction from Pratchett prior to his death, and the stupendous and creative marketing that Amazon has thrown at the project (a five-storey escape room in Soho; flocks of chattering Satanic nuns in the streets of Austin for SXSW) made it clear that they were giving the project the kind of gold-plated attention it deserved.
But it still took me a couple weeks to get around to watching it -- video time is really scarce in my schedule, and I'm perennially guilty over the years-long backlog of books on my TBR shelf that I'm hoping to review and/or blurb -- but I managed to remedy that yesterday, watching all six hours of the program (though I could only get through about half of it on the big screen in my living room: Amazon's DRM blocks Google's Chromecast for Android, and Chrome for Ubuntu -- the only GNU/Linux browser that talks to a Chromecast -- crashed repeatedly while trying to play it back, leaving me watching on my phone).
I loved it.
The TV show is very faithful to the novel (I failed to impress my wife by speaking some of my favorite lines aloud at the same time as the actors -- though I was sad that "What a shocking bad hat, as you young'uns do say!" didn't make the cut), and most of the changes are additive, with a series new historical scenes -- in the mold of Black Adder, Time Bandits or The Meaning of Life -- padding things out, giving the characters some depth and teeing up some very nice comedic effects.
The other changes are mostly updates to the furniture and logistics of the action, moving things from the late 1980s (with its nuclear anxiety) to the late 2010s (with our own set of anxieties), adding in mobile phones and the internet, exposing more of the inner workings of heaven and hell.
The casting is fucking brilliant. It's really a masterclass in how changing out white, male characters for more diverse players (including a gender-swap for God Herself) can add texture and relatability -- and it shows up how much blandness the traditional pale/male/stale choices for characters imparts to this kind of comedy (to say nothing of just how talented the cast are). Likewise the decision to surface the queer subtext between the angel Aziraphale and the demon Crowley, which throws all kinds of wonderful complexity into the mix, especially in the final episodes.
I don't often recommend movies or TV shows, because there are so many people out there better qualified than I am to tell you what's worth your time in that domain, but when it comes to sitting in judgment over adaptations of Good Omens, I feel pretty confident in my qualifications, given my longstanding and deep familiarity with and love of the material. The TV adaptation absolutely qualifies as worthy of your time and attention. It's one of those miraculous adaptations of a beloved book that is every bit as wonderful as the printed version, on par with The Princess Bride.