I'm just curious. Which do you think is harder: Telling a completely new story, or re-telling a classic? My knee-jerk answer is telling a new story. I mean, after all, you have to make up everything.
But then again, you get to make up everything. There are no adoring fans of the original to say "Hey! That's not how it goes!" I've read many re-tellings that are just...blah. It's just the same story, possibly a different setting, but no surprises. I've also read things that claim to be re-tellings, but I can't for the life of me figure out what the original story was. And then there are the books written by Gerald Morris. I love this man, and he is a genius. If you are a King Arthur/Knights of the Round Table fan (like me) or if you think the whole thing is ridiculous, you should pick up some of his Arthurian legends. It's easy to figure out which hero is saving which Damsel in Distress, but instead of the swoon-worthy romances these tales were intended as, they are roll on the floor funny, without being crude, disrespectful, or changing much of the story line. Like I said: Genius. And now I'm going to quit gushing and continue reading. Research, I promise.