“To make a good film,” Alfred Hitchcock once said, “you need three things: the script, the script, and the script.” Yet while it’s easy to find (and argue over) lists of the greatest films ever, it’s difficult to find a list of the greatest screenwriters. We decided to remedy that — by polling more than 40 of today’s top screenwriters on which of their predecessors (and contemporaries) they consider to be the best. To compile such a list is to pose a question: What is the essence of the screenwriter’s art? Plot? Dialogue? Character? All that and more? We left that judgment to those who know best — the writers. Here are their selections (ranked in order of popularity, with ties broken by us), and representative testimonials for each.