I have yet to read a Bacigalupi novel I didn't enjoy, and this one was no exception. An incredible near-future dystopia that seems incredibly likely given the already visible impact that global climate change has wrought upon the southwestern US. Both this book and Marc Reisner's Cadillac Desert, which features prominently in the novel, should be required reading for anyone living in that region. My only complaint was that the ending struck me as a somewhat sudden even though the plot was resolved. Nonetheless, I plan on including it on my Hugo nomination ballot.
4. Ancillary Sword, by Ann Leckie
For a variety of reasons, I didn't actually vote for the Hugos last year. One of them was that I didn't read this book before the voting period ended. Seeing as I wanted to finish read Ancillary Mercy in time for me to consider it for this year's nomination phase, it was something of an imperative I read this book first. I enjoyed the novel, much as I expected to, but I must admit that by the end of Ancillary Sword I still found myself occasionally distracted by the use of pronouns in the story.
5. Dark Orbit, by Carolyn Ives Gilman
While Leckie's Ancillary series touches upon how language alters our perception, Gilman goes a step further and explores how our perception of reality is completely reliant upon our preconceived notions of the world around us and the way our brains use pattern recognition to make sense of the world. Along those lines, the novel also explores how hidebound we are in the methods by which we use our senses to understand and navigate our environment. It was a fascinating read, and I am whole-heartedly, without reservation, going to nominate this one for the Hugo as well.