Hmm, well, apart from all the obvious ones (Terry Pratchett, Douglas Adams, Tolkien, Asimov, etc.) it's hard to think of any particular favourite authors. Tom Holt is pretty good most of the time, and I have a soft spot for Anthony Horowitz. Oh, and Iain Banks, although I'm not a fan of his science-fiction books. I can't think of any more right now, but they'll come to me.