My good friend Bastian had to tell me several times during many years that this is a must-read, before I actually got to it last autumn. I don't know why it did take me so much time. Perhaps I hesitated because it is an author collaboration? I have read and enjoyed both Gaiman and Pratchett before, and was perhaps a bit afraid that they would not be as good jointly as individual authors.
I was wrong of course, the fruit of their collaboration is brilliant, satirical, very, very funny, and refreshingly blasphemous (I have been told). Set during prophesied last days before the end of the world, and the final battle between the forces of heaven and hell, we follow a colourful set characters. Among them are an angel and a demon, both very comfortable with the world as it is, not particularly looking forward to the end of days, witchunters, a hell-hound, and of course the Antichrist.
Good Omens is funny, but it also doesn't cushion tragedy or stay away from criticising stupidity, religions, or authorities. It is a celebration to the unpredictability of human nature, and how this somehow give us the power to better good than all the angels of heaven and greater evil than all the devils of hell. I especially liked that blind adherence to a set of rules belonged to the otherworldly, but free will to the people of the world, somehow turning the concept of the divine on its head.
I now agree with Bastian: you need to read this book!