I read Three-Body Problem. I used topic search 
(yay me) and I see it was already mentioned once or twice but nothing substantive. The book is quite incomplete until you read the sequel, The Dark Forest. That explains a lot and it has some interesting perspectives on The Great Filter, without giving anything away. If you are into Great Filter stuff, I highly recommend these books.
There’s also a third book slated for later this year, I think? Death’s End. Not sure if the translation is the holdup or the actual writing.
Also, as it is translated from Chinese, I found it refreshingly alien in perspective, unlike most western sci-fi I’ve read. Sometimes this was tedious, but from an ideas perspective, you could really feel the cultural backwash rumbling up at times and coloring the perspective. It was nice.
