I first came across the book in 2017, bought it and was immediately hooked by the story.
Years passed, and when they announced the casts for the series, I was skeptical (I'm not a big movie/TV person) as I knew nothing about Michael Sheen and David Tennant.
Decided to give it a try, and boy, it's so good. Everyone is so perfectly casted.
The first season is based entirely on the book that's cowritten with Terry Pratchett. How you feel about the second season that'll be entirely from him and despite early assurances there won't be more, depends on how you think he is as a writer. I think he's matured, but certainly the book was a favourite that counted him as a writer because he had Pratchett to humanize and bring down the stakes to what I consider to be his storytelling tics to be clever and a bit grand.