For me, Pratchett is most comparable to Jonathan Swift with his imaginative vision and social satire. I deeply respect his ability to weave delightful characters in a fantasy setting while still giving insight into our own lives and world. By far, my favorite series within the Discworld series are the Tiffany Aching books. If you have not read them, I highly recommend getting a copy of Wee Free Men and give yourself the pleasure of losing yourself in his wonderful tale.