Which is only not on this list because it's recent enough that it's always been available as an e-book.
Pirate Freedom on its own is a pretty good book. Pirate Freedom read alongside Wizard Knight is a GREAT book. Both Christopher [last name obscured] and "Able" are transported into different, clearly imperfect worlds. "Able" immediately decides to be the best kind of man that world has -- a noble knight. Christopher...makes another choice.