I know we already have a book thread floating around in the darker regions of Foot, but what about authors? I consider Gabriel Garcia Marquez very capable of writing a good book for instance, but I don't consider him a great author, ditto Murakami Haruki and Brett Easton Ellis. I also enjoy books by people like Tim Parks, Jack Kerouac and Michael Herr, but for some reason don't list them as great authors when asked, so I'm interested in who other people think are/aren't great authors.
For me the two most significant authors of last century were George Orwell and Charles Bukowski, both for different reasons. Bukowski I feel showed the underside to America, and western life perfectly in Post Office, Women and Factotum, along with his short stories and poems. I think he showed us the neglected lives of Americans better than anyone had before, or has since, including William Burroughs (who I also think is a great author). Mainly I prefer Bukowski over Kerouac, Burroughs, Ginsberg etc. because I find his stories more based in reality, I don't think he hides anything from us. When he hits a woman for not getting out of his way he tells you that, when he can't get an erection because of how much he has drank he includes it, and when he gets the hell beat of him he doesn't try to make himself seem any more manly than a guy who got drunk, mouthed off and get beat up. Ginsberg and Burroughs sometimes let the ideas they wanted to get across get in the way of their work, especially in their latter years (I've always thought Junky to be Burroughs best novel), and Kerouac tries to hard to make himself look cool.
As for Orwell, well all those soundbites that say that no-one has documented the 20th century better than Orwell are true in my opinion. When you look at Animal Farm and 1984 and realise that he wrote about these things prior to them happening you see the foresight the guy had. Couple that with his honest looks at life in the working class (Road to Wigan Pier and Down and Out in Paris and London) and the Spanish Civil War (Homage to Catalonia) and you get a good picture of how talented this guy was.
Other than that I'd throw Hunter Thompson, Ernest Hemingway, PJ O'Rourke, and William Burroughs names into the great author hat