Do you know which actor or actress played in the most episodes of twilight zone? I know some are now big movie stars.

Like you mentioned, many of the actors that appeared in TZ episodes have gone on to have grand careers and many already had impressive credentials before appearing on the show.

The two actors that come to mind that appeared in the most episodes of The Twilight Zone are Burgess Meredith and Jack Klugman who each appeared in four episodes. I believe that was the most.