Mission impossible Greg Morris, Barbra Bain, Martin Landau....Peter Graves was recognizable.
For really obscure, there was Sally Baker. She was the hobo Kelly character, in a children's show.
Then there was Rodney Carl Anderson
Better known to the Portland Oregon audience as "Rambling Rod" it was actually broadcast till 1997. I had gone on the show when I was 9 or 10. That of course was 1969/70.
Outer limits actors
Vic Perrin: was the voice of the Control Voice, a distinctive and recognizable element of the show.
Ivan Dixon: Played roles in multiple episodes.
James Shigeta: Appeared in two episodes.
Kent Smith: Had roles in a couple of episodes.
David Frankham: Played a role in multiple episodes.
Philip Abbott: Also appeared in multiple episodes.
Robert Fortier: Played multiple roles.
Ted de Corsia: Played roles in multiple episodes.
Rod Sterling, who could ever forget that MC of The Twilight Zone or, Night Gallery.