my mother watched Guiding Light and As The World Turns… so I’ve got a few:
Guiding Light:
Michelle Forbes (Ensign Ro on ST:TNG and Admiral Cain on Battlestar Galactica) played Sonni, as well as her unknown, evil identical twin sister - Solita.
Elizabeth Dennehy (Brian Dennehy’s daughter, ST:TNG’s Lt. Cmdr. Shelby, etc)
Hayden Panettiere
Melina Kanakaredes (CSI, Providence, etc)
and a bit before my time… Kevin Bacon!
As the World Turns:
Scott Bryce (Popular, misc)
Amanda Seyfried
Buffy the Vampire Slayer Sarah Michelle Gellar was on “All My Children”, but she got her start as a little kid doing Burger King commercials.
I first “met” Melina as Victoria Metcalf on Due South. She was “the only woman Constable Fraser ever loved”–and a murderous, cheating, lying bitch.
The character, not the actress!
But I’ve never trusted her in any other role. The woman is evil!
Nobody has mentioned John de Lancie. Marvelous as Eugene Bradford on Days of Our Lives before being Q on Voyager.
Long before Knight Ridger, Baywatch, Jeckyll & Hyde and that infamous home video, David Hasselhoff was the second Dr. Snapper Foster on The Young & the Restless
Kevin Bacon was on a couple soaps early in his career Search for Tomorrow and Guiding Light.