If you are a discworld fan it's worth reading Strata, one of his earliest works.
This is set in a disc shaped world as well and you can see the early shape of the discworld concept (the world but also the style of the books). It's like seeing him work out his voice.
I love discworld a lot. But Good Omens is, for me, the essence of the craft of dark humourist fantasy. So many observations on humanity.
Strata was first Sir Terry book for me - I read it when I was teenager and was reading science fiction only. Imagine my suprise reading Colour of magic next, having strata in back of my head, waiting for the damn space ships to appear.
And they never did, not in a single discworld book I have read later in my life (dark side of moon aside coz its not part of the series).
Anyways ... I also recommend strata - the ideas on this book are so vivid and clever that they stay with You for the rest of your life (mechanical deamon with small wings using super fast teleportation as a way to implement flight always comes to my mind whenever I hack a solution with unexpected tools)
It is hilarious how much Strata owes to Niven’s “Ringworld”, if you have read that as well. It goes to its own places in the end but it sure does spend a lot of time as a direct parody of that book.
This is set in a disc shaped world as well and you can see the early shape of the discworld concept (the world but also the style of the books). It's like seeing him work out his voice.
I love discworld a lot. But Good Omens is, for me, the essence of the craft of dark humourist fantasy. So many observations on humanity.