Kasey Casem. The voice of Shaggy in the 'Scooby Doo' cartoons between 1969-1997, and again between 2002-2009
Don Messick. The voice of 'Scooby Doo' between 1969-1997. He also gave a voice to Bamm-Bamm Rubble [The Flintstones], Astro [The Jetsons], Muttley [Wacky Races and Dastardly and Muttley in Their Flying Machines], Boo-Boo Bear and Ranger Smith [The Yogi Bear Show], Sebastian the cat [Josie and the Pussycats] and Papa Smurf and Azrael [The Smurfs]