This Amazon review is trustworthy: The best edition to get is the hardcover University Edition printed in 2008. BUT if you want a cheaper paperback, make sure you get the authorized 2000 reduced facsimile of the 1988 Diamond Jubilee edition from the Philosophical Research Society (PRS). It's the only edition in print that is a true reprint of the original typography and illustrations in their correct places. All other editions are re-typeset, and some cluster all the color illustrations together rather than at the beginning of each chapter where they belong. The Reduced Facsimile is also the only edition that was authorized by Hall when he was still alive, and the only edition that contains ALL the original illustrations. The 2000 edition from PRS is very good quality with a sewn signature binding printed on heavy photo paper. DON'T get the Dover edition or the "Readers" edition!! Much of the value in this text is the beautiful typography and illustrations. It's not worth owning it otherwise.