Instruct: Classify Amazon reviews into positive or negative sentiment
Query: My favorite sci-fi novel

This is a fabulously well-conceived book. I wouldn't call it a utopia, because it is more realistic than that, but it's not a dystopia either. Le Guin has carefully thought through the consequences of anarchism and idealism, while vividly portraying a living world in which her ideas evolve. The attention to detail has made this book stick in my mind years after reading it. If you like sci-fi with more than guns and battleships, this is an intellectual treat.