Faust, Part I (Johann Wolfgang von Goethe, preliminary 1806, revised 1828)

Goethe's version (Penguin paperback here) of a well-known tale with centuries-old roots.  It's interesting that Goethe (bio here) was struggling with the story for much of his adult life - Part II wasn't even published until after his death.  Part I came out in preliminary form in 1806 and was issued in revised form in 1828.  So "different" Goethes were working on different parts of the work.

I ordinarily don't read plays, and have trouble getting through them.  Should work on that.  But this one was short.  Faust is frustrated with his inability to possess knowledge; cuts the famous bargain with the devil (signed with a drop of blood, per picture); starts hanging out with Mephistopheles and having various adventures (including the scene where wine is tapped from the barroom table); corrupts Gretchen; kills Gretchen's brother; attends the witch-gathering; seeks to spring Gretchen; etc.

The devil seems to be the most "human" character in these types of stories, which I find interesting.

Numerous stage versions, numerous adaptations.  I think the critics generally considered this a great work though flawed in construction, I read that Part II doesn't flow well.