Boing Boing has published an article by Monte Beauchamp who has identified 16 cartoonists he argues were the early trend setters or trail blazers by which others followed. He includes: Walt Disney, Winsor McCay, Harvey Kurtzman, R. Crumb, Osamu Tezuka, Charles Schulz, Jerry Siegel and Joe Shuster, Hergé, Hugh Hefner, Jack Kirby, Al Hirschfeld, Rodolphe Töpffer, Lynd Kendall Ward, Chas Addams, Dr. Seuss, and Edward Gorey.
Monte has a book out called Masterful Marks: Cartoonists Who Changed the World