Terry Pratchett’s Discworld series. Like the whole thing. Can’t pick a favourite.

I would disagree with that. The last 3-4 books were... Not good. He was already showing signs of Alzheimers by then, and it was reflected in his writing. He died shortly after the final book, and, while it had flashes of his brilliance, it was clear that he was having a very hard time writing anything coherent by that time. Up to that point, he was fantastic. "Small Gods" is one of my favorite books about religion and belief, and he disguised it as comedic fantasy.