“Ancillary Justice” by Ann Leckie is an excellent book, though not an easy read. The plot: A ship known as the Justice of Toren is an AI unit, and to carry out its wishes, makes use of “ancillaries” – basically, corpses converted into extensions of the AI. But the Justice of Toren was annihilated, with the exception of a single surviving ancillary known as Breq, and Breq is on a quest for revenge to destroy those who nearly destroyed her.
What makes it stand out from the usual sci-fi fare is that it has incredible depth, thematically (Ancillary Justice has won a boatload of awards, by the way). Breq, for example, can represent the way we express ourselves. In other words, I act differently around my mother than I would around a friend, my husband, or my boss. I have different “ancillaries,” so to speak, but it’s still all coming from the same brain.
Justice of Toren is thousands of years old, and can simultaneously communicate with all its ancillaries; yet Breq has developed subtle little personality traits that distinguish her from the other ancillaries from Justice of Toren (she likes singing, for example).
The book also takes a feminist approach, most notably in the way every character is referred to as “she.” Much has been made of its similarities to Ursula Le Guin’s Left Hand of Darkness (another excellent book that explores gender themes). The end result, though, is that it highlights how meaningless gender constructs are, and puts a real emphasis on character and action. Besides, if gendering a character is important to you, it’ll all sort itself out in your head anyway.
The writing itself is brilliant, though like I said, it’s not an easy read. But this is the kind of book that exemplifies how science fiction can be a potent commentary and critique of humanity. Sounds lofty? Sure is. But so is this book.