Good ol' Freaks in Barcelona. Just when you think you know everything that's coming out and what you want they surprise you. The new book published by Prestel serves to my mind as being the definitive Mucha book I've seen. The posters make up the first part of the book but it goes on to highlight the rest of his career as demonstrated in an exhibition doing the rounds.
Beautiful stuff and a collection that pretty much has everything you could want in a book about a guy who (along with Gustav Klimt)inspired so many graphic oriented illustrators in comics and made Hughes' Wonder Woman, JH Williams' Promethea and Quesada's Daredevil what they are today.
Find it here