Philip K. Dick's Hugo-winning novel: The Man in the High Castle:
[The flap-copy from the hardcover]: In a hilltop cabin, his "high castle," surrounded by barbed wire, a solitary writer conceives an imaginary account of history - in which FDR was not assassinated, in which Italy betrayed the Axis countries and the Allies won World War II. His novel, The Grasshopper Lies Heavy, is of course banned in the eastern portion of postwar America, dominated as it is by Nazi occupation forces. But in the Pacific States of America, which Japanese victors control and where the Oriental race is superior despite its puppet white government, where the I Ching - the ancient Chinese Book of Changes which predicts the future and understands the present - has replaced the Bible and a more permissive, humane philosophy dominates, the novel is tolerated by the authorities. And its incredible, fantastic image of a "mythical" postwar world is glimpsed against the "real" world of the present. Against this background of a globe controlled by Germany and Japan, Philip K. Dick tells this bizarre, hilarious, terrifying, electrifying tale: of a dealer in historic U.S. trivia who maintains an exclusive antique shop in San Francisco; of a Jewish artisan hiding from the Reich racial laws and of his estranged wife languishing in the backwater country of the Rocky Mountain States; of a travelling "Swedish businessman" who is much more than he seems; of a Gestapo killer sent on the track of the man in the high castle.
The Man in the High Castle won the "best novel" Hugo Award in 1963 (for books from 1962.) It easily makes my personal "top 100" list, and is the kind of book I would point to and say "this is the kind of book that should win a Hugo," by showing that a SF novel can be a serious novel of ideas. One of my favorite parts is the misunderstanding involving a Mickey Mouse watch - all of the details and motivations are just right, and reveal the nature of the people or cultures involved. I strongly recommend this.