I don't know if The Dark Forest by Cixin Liu is eligible or not; the translation just came out last year, but I don't know the Hugo eligibility rules. If it is eligible, it's my favorite book I've read in the last year. The Three-Body Problem was the book I really wanted to win the Hugo last year, even with the controversies, and I was thrilled it did. I'd be super thrilled if its sequel won this year, because quite honestly the book is incredible and I'm waiting very impatiently for the last one to come out this year.