The members of the Writers' Guild have picked the 101 Greatest Screenplays of All Time.
The list has the usual problem with attempts to single out the screenwriter's contribution for praise: it assumes that the credited screenwriter is the creative force behind a movie, whereas much of the time a screenplay is a collage of contributions assembled according to the specifications of whoever is in charge of the movie (the director or the producer or, if there's a turf war going on, both). Picking Casablanca as the number-one screenplay of all time kind of points up the problem. Casablanca is a wonderfully well-written movie, but it's hardly a triumph of the screenwriter's art; as I've noted before, the script of Casablanca is a hodge-podge by half-a-dozen writers, and the coherence of the finished product is due to the producer, Hal Wallis, who knew what he wanted and was willing to hire and fire as many writers as was necessary to get it. Casablanca is, sad but true, an example of the good results that a producer can get with the script-by-committee system.
As to the list as a whole, it's no better or worse than most such lists, though ultimately it just seems like another top 100 (sorry, 101) movies list. And the failure to include any screenplays by Samson Raphaelson is baffling, given that his scripts for Ernst Lubitsch really are works of art in themselves, even separate from the finished movies.
A more interesting list would be a list of great scripts that were made into disappointing movies -- in other words, examples of the screenwriter's art, separate from and superior to the director's art. I might freakishly nominate Lover Come Back (Stanley Shapiro and Paul Henning), an exceptionally funny script -- a social/cultural satire disguised as a romantic comedy -- let down by the generic directing, art direction, photography and acting of the finished movie. In other words, reading the script is more fun than seeing the movie.