Oh this could be a whole thread all on it's own, I feel guilty being the only person who gets to answer this question.
I have so many books that I read over and over again, and so many favourite authors.
But if I had to pick just one, I love 'The Valley Of The Horses' by Jean M Auel. It is the second book in the Earth's Children series which begins with The Clan Of The Cave Bear. Which was made into a really good movie starring Darryl Hannah.
And because I know lots of others will have their own choices.
I hope nobody minds.
What is your favourite book?