My first nomination was going to be:
Me, Myself, They: Life Beyond the Binary, by Joshua M. Ferguson, a leader in the fight for non-binary rights in Canada and beyond. An interesting and important book with some flaws, but none that were critical. However, it's not available as an eBook in Australia, and it has gone up in price in North America, so I think I'll have to pass. But having said that, I'd encourage those of you who can get your hands on a copy to read it. If you don't learn something, and don't have to do a bit of re-examination, then you've probably already gone beyond the basic cisgendered pronouns. However, I encourage you to avoid the audio book. A perfect example of why authors shouldn't read their own books in the vast majority of cases.
I'll be back tomorrow with a nomination. Or two.