Mary Kay Bergman
Mary Kay Bergman was the fourth actress to provide the voice of Daphne Blake in the Scooby Doo series. Technically, Bergman's contribution were not to any of the television series. Rather, her work was all on animated films, which includes Scooby Doo and the Alien Invaders, Scooby Doo and the Witch's Ghost, and Scooby Doo on Zombie Island. Sadly, Bergman passed away on November 11, 1999.
Prior to her passing, Bergman was an accomplished voice actress. In addition to providing the voice of Daphne for a short period, Bergman provided character voices for animated movies and shows such as Beauty and the Beast, Toy Story, and Buzz Lightyear of Star Command. Her most noted work was on South Park. Prior to her passing, Bergman pretty much voiced every female character on that show.
Her friends and family have maintained a site dedicated to Bergman's legacy.