My favourite all-time work of fiction: Lord of the Rings. My favourite all-time nonfiction book: Guns, Germs, and Steel. Ask me again next week, you'll get a different answer. ↗
Writing fiction is for me a fraught business, an occasion of daily dread for at least the first half of the novel, and sometimes all the way through. The work process is totally different from writing nonfiction. You have to sit down every day and make it up. ↗