Self-serving as I am, I used to advocate for B&B to hire Anna Stuart to play Eric's long-lost sister. I wanted her on my screen, no matter who hired her! Her eye for style and fashion (Donna was always so elegantly put together) always made me think she'd be a natural for that show. This was back when Susan Flannery was still on the show; I thought they'd make an interesting rivalry because AS's character would know Stephanie from "way back". I think AS is now semi-retired, spending most of her free time bailing her actor/environmental-activist husband James Cromwell out of jail.
Also in the 'self-serving' file, I think Stephen Schnetzer and Alice Barrett-Mitchell would be great as GH's Dr. Jeff Webber and his ex-wife (Liz's mother), who could plausibly return to work at GH. I'd love to see SS and Leslie Charleson rekindling a decades-old romance, with AB-M as his shrewish ex trying to enlist her daughter's help in winning Jeff back. But Scotty might be a better match for her.