I've recently purchased Oliver Byrne's reproduction of Euclid's Elements. It's a beautiful tome, that's rather unique in its presentation of the material as it demonstrates many of Euclid's proofs as lurid and lusciously coloured geometric figures. See below:
So, my question is:
What are some other mathematics books that convey a topic in a manner that breaks from orthodoxy?
Now I doubt there are very many books that meet at the intersection of art and mathematics such as this, so this should not be the sole criteria by which the 'unconventionality' of a book should be judged. In all probability any departure from orthodoxy will likely manifest itself in the form of pedagogical organisation/exposition distinctions, and so this should be the predominant criteria by which you should judge a book's eligibility for recommendation. It would also be appreciated if you could provide a justification as to why you believe a given book is unconventional.
I'm sorry if this is off-topic, hopefully I can at the very least expose a few people to this lovely book.
I will recommend again "Mathematics for the Million" by Lancelot Hogben. $15 at Amazon.