Again, the actual winner has everything you'd want in a classic science fiction novel - mystery, problem-solving, and big ideas - which undermines the only puppy complaints that are anywhere in the neighborhood of valid. This novel's win was part of a strong anti-sad puppy final result that included "no award" winning many categories that the slate had dominated (though the book had some support from puppy voters, which may have skewed the results).
The Three-Body Problem begins during China's Cultural Revolution in the late 1960s, in which activist students fought viciously over Communist ideology in an effort to renew the principles of China's Revolution. This included widespread persecution of intellectuals, and acts of humiliation and violence against anyone believed to have committed ideological crimes. Not only is this an interesting place to start a novel set in China, it gives Liu a couple of thematic points that will recur in the novel: the sense among some of the characters that humanity is too depraved to continue to exist as it is, and also a belief that empirical science should transcend political ideology.
Ye Wenjie witnesses the brutal beating of her father, a theoretical physicist, during the cultural revolution before being sent off to Red Coast, a Chinese SETI (Search for Extra-Terrestrial Life) program, for political rehabilitation. Her story is told in flashback at various points in the book, though once an author introduces a SETI project in a science fiction book, you probably have some hint about the plot. In the present (well, near future), we follow nanomaterials researcher Wang Miao. Wang is contacted by the Chinese police, including the book's most colorful character Investigator Da Shi, along with the CIA. They're investigating the recent deaths of several scientists around the world. After having his own surreal experiences (some of the best parts of the book), Wang ends up exploring a virtual reality video game called The Three-Body Problem. In the game, Wang has to figure out the seasonal cycles on a planet that has irregular periods of intense heat and cold.
I really came to enjoy this book a lot. In fact, it has just about everything I want out of science fiction - big ideas that don't ignore human societies and historical thinking and context. I will say the prose was a little plain. In a translated work, it's hard to say where the blame lies, but I've read a fair number of Ken Liu's stories, and I think he's a fine writer, so I'd wager that Liu Cixin's prose is probably fairly unadorned (though very clear) in the original Mandarin. A bigger problem is with the characters. There is attention paid to their motivations, but beyond that they're all pretty flat. Ye Wenjie is the most well-rounded, detective Da Shi is a fun archetype, the main character is kinda dull, though that maybe helps him as a point-of-view character - he is easy to project onto. Actually, I have to say that adding together the stock characters and unadorned prose alongside the great ideas and logical storytelling, I was reminded a lot of Isaac Asimov (who gets name-checked at one point). Asimov was very influential in my early sf reading, so it was a pleasant association, even though not all of those characteristics would be considered virtues in most novelists.