This is an impossible question to answer; there are far too many! But I'll list Robert Rankin, John Grant and James Lovegrove as just three excellent writers who don't get nearly enough recognition. If you've never read them, do.
Answer to Prospero - no you shouldn't start reading Stine ... only if you are under the age of 12. When I was 10, I loved reading his books! think he writes just children's books. His books get children to like reading more. The stories are very interesting. Thank you for answering my question ... and I hope more people do!
I'll go with prospero's choice of Hemingway as one of my favourites, and one I go back to. Others would be Graham Greene, Bruce Chatwin and Dostoyevsky, but this is only a short list. It's impossible to pick just one. Current faves include Anna Kavan and Peter Vansittart, but, like many people, I like what I'm reading at the time.
As very few women have been recommended here I'll add a few: Louise Erdrich, Ellen Gilchrist, Anne Tyler, Sara Paretsky, Sheena Mackay, Barbara Anderson and Jane Austen
My favourite writer right now is James Harland, who has a new book out called The Month of the Leopard - I sampled it at www.jamesharland.com. It is a tough, engaging, romantic read, and every word is beautifully put in place. Highly recommended.
My favourite writer is Stephen King - especially his early novels, 'Christine' and 'Salem's Lot'. Their length is down to the time it takes for 'ordinary' people to realise that extraordinary things are happening to them, and they have to be dealt with.
King's fame is encapsulated in an incident when he was eating a quiet dinner with his good friend Bruce Springsteen during the latter's 'Born In The USA' phase, when he was one of the biggest rock stars on the planet. Seeing a star-struck teenager advancing towards the table, Springsteen produced a pen and a ready smile - the teenager ignored him, and advised Stephen King that he was her favourite writer ever, could she have an autograph? Now that is being a famous writer!