The fancy, official, academic standard edition of "The Pilgrim's Progress" is Oxford University Press’s Wharey/Sharrock edition of 1928/1960. Produced by the press of a university that would not admit non-conformists for another 180 years after Bunyan’s famous publication, and prohibitively expensive, there is no reason to commend that version further.
In fact, for access to the first edition text with subsequent revisions in Bunyan’s hand, the Oxford World’s Classics version, edited by Bob Owens gives great value (still Oxford, I know, but affordable!) He includes a limited number of woodcut illustrations that had begun to inserted with the text by Bunyan’s publisher, Nathaniel Ponder, while Bunyan was still alive. Bunyan’s own marginal comments and scripture references are preserved, and a good set of explanatory notes help with some of the language and historical context. If you want to read Bunyan in all his unvarnished glory as a non-university theologian, the original text and his pithy choice of phrasing is for you.
Evangelical ministry Desiring God not long ago published a version of Part I only, which carries a laudatory essay on John Bunyan by John Piper, and includes another evangelical favorite John, in this case Newton’s 1776 introduction to The Pilgrim's Progress. The typeface is clean, the marginal Bible references (but not Bunyan’s comments) have been tidied into footnotes. It is a shame that Bunyan’s essay explaining why he is bold to write an allegory is not included. For the Author’s Apology another version would need to be consulted. On the flip side, Desiring God make their edition available for free as a PDF, but you can also buy it as a well produced paperback.
When it comes to updated language versions, there have been plenty. "The New Pilgrim’s Progress" or "Pilgrim’s Progress in Today’s English" do not read quite as accessibly as "The Pilgrim’s Progress: Faithfully Retold by Cheryl Ford." What I like about Ford’s version is that she keeps "The Author’s Defense of His Book" at the beginning. She also keeps the marginal bible references and comments as marginal notes – to engage the eye during reading, and not just as possible follow up for the academic reader that footnotes inevitably suggest (with a little supplementation of additional Bible references on the versions of Bunyan’s life time, as far as I can see). Ford includes both parts together, as has become standard too. Inevitably some of Bunyan’s idiosyncratic grammar and earthy word choice is lost, but nothing is abridged. This is the full text.
Lastly, if you wanted to access some critical comment on the text as it has been interpreted and received, Cynthia Wall’s Norton Critical Edition is still wonderfully slim, but nonetheless carries a judicious selection of material on historical background, and provides tasters of some of Bunyan’s other writings, and even an extract from the earliest copycat improvement by T.S, thought be fellow Baptist preacher Thomas Sherman.
I’ll say more about the map that graces the Norton edition, and other maps, in another post. If you’re inclined to "read"-by-listening, I know there are also audiobooks. I’ve enjoyed David Shaw-Parker’s reading for Naxos, but I know more affordable versions are out there. Happy hunting!