Ancillary Justice by Anne Leckie
This was an unusual read for me; a piece of more hard science fiction than I'm used to. I tend to be more in the Ray Bradbury camp of science fiction that is light on the hard science specifics and much more philosophical about the ethics of technology and progress.
Except that is exactly what this novel is about. The main character is a human that was made into an AI and now is a single consciousness made up of multiple bodies. This consciousness is trying to right a wrong and the mystery of what she is trying to do and why is a compelling reason to pick up the book. The consciousness has several names: Justice of Toren and One Esk.
I would say this novel succeeds in two major ways. First is that the story very subtly completely challenges everything we believe about a gender binary. Characters are not strictly male or female and instead of that issue being biological, it is linguistic. The protagonist moves through different languages that either gender or do not gender things. It's a completely fascinating "feminist" take in that it quietly forces you to see just how male our particular world is.
The second way it succeeds is by forcing you to contend with the idea of multiple consciousnesses in a very relatable way. I can't say that AI is a topic that especially interests me, but the idea of being a multiple body and viewing the world knowing that you are more than a body was fascinating.
This is the first in what is supposed to be a trilogy. I have to be honest and say I don't feel overly compelled to pick up the next book--not because this wasn't exciting and a really stylish experience but because I got a lot out of the premise and I don't know how much more a sequel will offer. But if you are looking for a really interesting story made up of multiple intelligences, revenge and a fascinating culture, I would recommend Ancillary Justice.