Johnny Carson hosted NBC's "The Tonight Show" for thirty years, with guests from every walk of life, including many old and new celebrities. (Comedian Jay Leno took over "The Tonight Show" when Carson retired.) Singer Mike Douglas hosted a popular, long-running show, co-hosted by weekly guests. Merv Griffin, David Frost and Dick Cavett also had long-running talk shows. Dr. Joyce Brothers was one of the first women to host a national talk show. Other women followed as hosts, including Oprah Winfrey, Joan Rivers, Ricki Lake, Rosie O'Donnell, and Ellen DeGeneres.