Ancillary Sword, Ann Leckie (Orbit US; Orbit UK)
This one brings a ton of buzz with it, and could be the book to beat on this list. The novel picks up in the midst of a massive space opera, with an empire teetering on the brink. It’s also the sequel to Ancillary Justice, which piled up the Hugo, Nebula, British Science Fiction, Locus and Arthur C. Clarke Awards a few years ago. It’s big, and can be dense, but it’s worth it for sci-fi fans who devour world building and massive sci-fi concepts. The New York Times notes the author “thumbs her nose again at science fiction tradition,” and asks some great questions about AI and what it means to be human.