Terry Pratchett's Colour of Magic is such a wonderful book. It introduces you to a wonderful new world, though I think you need a slightly warped sense of humour to appreciate it. Now I look forward to each new book and have the whole collection. Such a shame that he is ill.
I love the luggage - which you can never lose and seems to hold everything you will ever need. And how photography works (little imps inside the box busy painting the scene). Wizards who can't do magic/never do magic. Really you can't explain it, you just have to read it.
I also am a Terry Pratchett fan and have all his books. His world is whacky but so enjoyable. The characters are likeable : Sam Vines, Carrot, Lady Sybil, Nobby, Angua, even Gaspode the Wonder Dog. Trying to describe the "plots" and the Disc World to anyone else is so difficult and yet everything makes sense to a Discworld fan.
Have you read "Good Omens"? I can recommend it.
I just could not get into Good Omens. perhaps I will try it again, I am sure I have it somewhere - the trouble with having over 1000 books and not enough bookshelves is finding anything!