Strange, I typed a response to this a couple weeks ago... maybe I didn't click "post"?
My current favorite book, being the geek that I am, is Tom Leoni's translation of the work of the 16th c. fencing master Salvator Fabris. Or at least, that's my favorite at the moment. Its my favorite because of just how clearly he explains fencing theory, in a way that just was done in most other contemporary written sources. Heck, he explained things better than some modern sources. The work of Fabris has given me a much better understanding of many of the universal principles of martial arts in a way that my years of Aikido, Tae Kwon Do and sport fencing never did.
