But I did get into Discworld on the ground floor. I got The Color of Magic, the very first book, in the mid-80s before the second book (The Light Fantastic) ever came out. It was a hardcover from the Columbia Science Fiction Book Club, and that's the dust jacket above. I think I got it on the strength of the catalog's description, where it was no doubt compared to Hitchhiker's Guide to the Galaxy, which I'd loved. And it WAS a little like that, only with fantasy. And I loved the idea of a flat world sitting on top of four massive elephants, themselves resting on a gargantuan turtle, swimming through space. It evoked Ancient Egyptian and Indian ideas of the cosmos. The story itself was an amusing trifle, enough to get the second book, which was okay.
But with the third book, Equal Rites, the previous protagonists (a less-than-competent wizard and Discworld's first tourist) were jettisoned in favor of new characters, and though Pratchett would return to the book's witches fairly often, each Discworld novel from then on might focus on an entirely different corner of his universe and a new cast of characters. He kept it fresh, and I was soon grabbing the paperbacks before the book club could ever offer sturdier versions - no waiting!
Call it heresy if you will, but I thought Hitchhiker's got progressively less funny and interesting, whereas Discworld got better over time. I suppose I should count myself lucky that there's so much left for me to discover - some 30 books just in the Discworld series and several more besides. We would all have been luckier still to have kept Pratchett on Earth and in health for longer.