Ok, fine, nobody was willing to claim that any film could live up to the title of being the definitive interpretation of a play. I have to concede.
But I'll take Alexi's idea and open up a more specific topic -- definitive cinematic versions. Will that make everybody happy? What is the definitive cinematic version of, say, The Tempest?
What's a better definition for "definitive" in this case - would you call it the one you'd recommend to a friend as their first exposure to the story? Or would you go the other end of the spectrum and say, "No matter how many film versions of X you've seen, you simply must see Y."