Della Street, the eternally faithful Gal Friday. No mere phone-operator or calendar juggler, she was a quick-witted, brave, tireless comrade. She got put on the stand in season one by Hamilton Burger, because she'd been involved in one of Mason's Trademark Theatrics.

(Barbara Hale, who played the character, is the mother of William Katt, who played the title role of "The Greatest American Hero" show in the 80s. Believe it or not.)