Awww, man. I think Elmer Bernstein had the greatest number of classic soundtracks. I especially loved that shuffling piano used in the theme for Ghostbusters. Not the Ray Parker Jr. track, the one called "Main Title Theme From 'Ghostbusters'".
Damn, looking over the scores he's composed at IMDB... How could I forget the theme to "The Great Escape"? Possibly his most memorable score. "To Kill A Mockingbird" was absolutely beautiful.