(Agence France-Press)(pg. C9) Billy Crystal, aboard a mock-up of the Titanic, served as host of the 70th annual Academy Awards ceremony. (Associated Press) Matt Damon, left, and Ben Affleck won the Oscar for best original screenplay, for ''Good Will Hunting,'' in which the actors also starred.he other Oscar nominated films were ''As Good As It Gets,'' ''L.A. Confidential,'' ''The Full Monty'' and ''Good Will Hunting.'' The Oscar winners were selected by the 5,371 voting members of the Academy of Motion Picture Arts and Sciences.