Here's how I'm leaning at the moment (behind the cut)...
I'm confident about my placement of the bottom three, but am still not 100% about my ranking order of the top two.
1. Ancillary Justice by Ann Leckie
I enjoyed this book a lot. Interesting world, story, and characters. Engages my imagination and makes me think. Can't wait for the sequel!
Some of my (spoilery) thoughts on Ancillary Justice here.
2. Wheel of Time by Robert Jordan
There just isn't a lot more to say about this one, other than what's already been said. Pretty much, you're a fan or you're not. I'm a fan. I've enjoyed this enormous story over many many years, it has engaged my imagination and made me think about a lot of things, and the characters feel like friends I'm sad I'll never see again.
I have some not particularly spoilery thoughts about the series and its eligibility for the Best Novel award here, and I just want to add a bit more. One of the major complaints I've seen about the series is that it's very derivative of Tolkein, and that there is nothing else to the story. Yes, it does have some elements of Tolkein. But it also has elements of tons of different myths, legends, religious stories, other literature, etc., taken from many parts of the world - China, Japan, India, Europe, the Middle East, more. And that's actually the point. It's the Wheel of Time. "The Wheel of Time turns, and Ages come and pass, leaving memories that become legend. Legend fades to myth, and even myth is long forgotten when the Age that gave it birth comes again." Many of the legends and myths that the characters hear about in the Wheel of Time are from our real life modern or recent history. Many of our modern day legends and myths are seen coming around again in varying forms in the Wheel of Time books. Look at the Heroes of the Horn! We almost know the names and the vague storylines of some of the series characters because they've come around, again and again, with the turning of the Wheel. But how will it spin them out differently THIS time? I love this. So many almost-familiar stories, mish-mashed and re-wrought, within the story itself (stories within stories) and also from other real-world sources. OK, I'll stop - this could turn into another whole blog post all by itself.
3. Neptune's Brood by Charles Stross
By the end of the book, I was really having a lot of fun with this story, and was really enjoying a lot of the concepts. I didn't enjoy the extra-heavy exposition, to the point that I almost put the book down before it got really fun and interesting.
Some of my (spoilery) thoughts on Neptune's Brood here.
4. No Award
Parasite by Mira Grant
I really expected a lot more out of the Parasitocalypse. Also, I know this author is much, much better than this.
Some of my (spoilery) thoughts on Parasite here.
The other troll will also not be listed.