Joss Whedon
He also wrote helped edit and rewrite the scripts of Speed, Waterworld, Twister and X-Men. Except for Speed, not much of Whedon's work stayed in the final versions of any of these screenplays. He has said that he had a good script for Alien: Resurrection, which was ruined by its director Jean-Pierre Jeunet. His Waterworld script was thrown out. Only two of his lines were kept in the final script of X-Men. Even the Buffy movie was very different from what he originally wrote. According to Graham Yost, the writer of Speed, Whedon wrote most of its dialogue.