Remake or mistake?

I like Shakespeare. I took a Shakespeare year in high school, essentially. Two electives, one for the fall, one for the spring. We watched the movies rather than read the plays, and while we did have tests, they were easy if you'd been paying attention. My high school English teacher had concentrated on Shakespeare in college, and his love of the work combined with his command of the material made for an amazing experience which has stuck with me.

From Wikimedia Commons

So I get kind of excited when I see new Shakespeare movies come out. Romeo + Juliet came out at a prime time for me, both during my love for Leonardo DiCaprio and also my burgeoning love for Shakespeare. It was truer to the text than the Zephirelli version and had Leonardo DiCaprio and John Leguizamo and Harold  Perrineau (whose Mercutio has been, in my eyes, unrivaled); what's not to love? More recently, the Gerard Butler and Ralph Fiennes Coriolanus was amazing (and I hear Tom Hiddleston's stage performance thereof was as well). I've watched Kenneth Brannaugh's Hamlet (my favorite Hamlet, though The Lion King was great too), and most recently, Patrick Stewart's Macbeth (oh, those witches!)

So. Why do I enjoy derivative works of Shakespeare, and endless remakes? Why do I not like other remakes? (Red Dawn, I'm lookin' at you. You would've been fine if only the serial numbers had been filed off. Not a great film, but one more worth the time.)

I probably don't have an answer for that in this blog post, but it was one of those topics which made me see fit to turn my eye inward. Self examination is healthy, I've been told.

What makes something fan fiction and something else derivative? Is it just time? The Story of Edgar Sawtelle: A Novel (P.S.) holds a higher place in my mind than Fifty Shades of Grey, but both ultimately came from another work, which the authors changed and made their own. And the sex parts have nothing to do with it; sex alone in a book will not make me think it's "bad", though to be fair I never felt Lolita was as good as its first page. Its first sentence.

So what makes the crucial difference between Spike Lee's Oldboy and Hamlet 2000? Between the American version of The Killing and the 1998 remake of Psycho?