We must give thanks to the talented voice actors who lended their voice talents to the series. So, here is a page with a list of all the people who did the voice work and which characters they did.
I used Sonic HQ as a reference for this list.
Sonic the Hedgehog-- Jaleel White
Miles 'Tails' Prower-- Bradley Pierce
Princess Sally and Nicole-- Kath Soucie
Antoine-- Rob Paulsen
Dr. Ivo Robotnik-- Jim Cummings
Snively Robotnik-- Charles Adler
Uncle Charles-- William Windom
Bunnie Rabbot-- Christine Cavanaugh
Rotor-- Mark Ballou and Cam Brainard
Dulcy-- Cree Summer
Lupe-- Shari Belafonte
Ari-- Robert Mugleston
King Acorn-- Tim Curry
Young Sonic the Hedgehog/Additional Voices-- Tahj Mowry
Young Princess Sally & Additional Voices-- Dana Hill
Miscellaneous Characters-- Michael Bell, LaCrystal Cooke, David Corban, Dave Fennoy, Alaina Reed Hall, Dorian Harewood, John Kassir, Katie Leigh, Nancy Linari, Victor Love, Hal Rayle, Lindsay Ridgeway, Charlie Schlatter, Frank Welker