Okay, new rule. Once a film reaches a level of greatness such as The Wizard Of Oz, it is under no circumstances allowed to be sequeled, remade, prequeled, spin-off'd...you name it. The film should remain alone as one timeless classic...and never duplicated. We as the movie-going public should decide which films are so timeless that they cannot be tortured with continuations. I would nominate:
-The Wizard Of Oz
-Mary Poppins
-E.T.
-Avatar
-Forrest Gump
-The Sound Of Music
-Jurassic Park (two crappy sequels too late for that film)