Well, heck, I always considered Eve as one of the famous ones.
TBA, of course.
There’s at least one SF author posting here, and at one time there were several - I don’t know if any of them are still hanging around.
Also at least a couple of non-fiction authors besides Eve - Cal Meacham, for example.
There’s aha, our resident legendary musician (although I think there are several other posters who have at least a nodding acquaintance with the musical ‘bigtime’).
Loren Coleman posted here briefly, but IIRC he signed up to defend himself from criticism in a SD Science Staff report, and was promptly handed his ass by several of our more illustrious posters. (It was a pretty damn funny thread, too.) Here it is!: Cryptozoologists.
I know I’m missing some folks, but my brain seems to have taken a coffee break, so I guess I’ll go feed the cats before they revolt and have me for lunch.
A couple of the actors from the TV show “Firefly” posted pretty regularly to the offical MB for the show on the FOX website, and I think they wandered over to the Television without Pity boards a few times.