He left some really good work behind in assorted films and television appearances (his work on Columbo was really good and he got two Emmys for it), but I think my favorite McGoohan shows were Secret Agent and The Prisoner. Especially the Prisoner. He didn’t just star in it. He wrote and directed episodes (some under pseudonyms). The show was very much his baby. Nobody made anything like it before its debut in 1967 and I would argue that it’s never been equalled or approached since.
He will be missed.