I’m going to take a stab at it and say Leave It To Beaver (1957).
Based on the primary cast of 14 (from the IMDB):
Alive: June, Wally, Beaver, Eddie, Lumpy, Larry, Gilbert, Tooey, Richard
Dead: Ward, Whitey, Mr. Mondello, Mrs. Mondello, Gus (the fireman)
Alive: 9 (64%)
Dead: 5
Any show older?
“Your Show of Shows” debuted in 1950. Of the “Big Three”, Caeser and Reiner and still alive. Several of the others are still with us including Howard Morris, Bill Hayes, Robert Merrill and such. Many of the writers are still around (and quite famous) too. Amazing.
The IMDB doesn’t really break down cast by importance/regularity.
?I believe one of the “showgirls” on YSoS was later one of parents(?) on “Mad About You” and a clip was used (with Reiner) in one episode.?
According to the trivia part for it on IMDB, The Sky at Night is the world’s longest running programme with the same presenter. Patrick Moore has been presenting it since 1957 and, to my knowledge, still does.
Father Knows Best moved to TV from radio in 1954. Of the six permanent cast members, four are still alive, for a 66.7 percentage.
Sorry, Beav.
I got you all beat.
The Mickey Mouse Club (1955-1959)
According to what I can find on the IMDb, it’s:
Alive:
Sherry Alberoni, Sharon Baird, Bobby Burgess, Lonnie Burr, Tommy Cole, Johnny Crawford, Annette Funicello, Darlene Gillespie, Don Grady, Cheryl Holdridge, Tommy Kirk, Cubby O’Brien, Karen Pendleton, Paul Petersen, Doreen Tracy
Dead:
Jimmie Dodd, Julius Sumner Miller, Roy Williams
So, it’s 15-out-of-18, or a whopping 83% still alive.
Anybody think they can top that?
I could well be wrong, but wasn’t Tommy Kirk just a guest (The Hardy Boys segments) and not a real Mousketeer?
And I’ve met Tom Kirk TWICE at conventions! One of the truly nicest guys EVER.
Sir Rhosis
The Dick Van Dyke Show has a pretty good batting average: only Richard Deacon and Morey Amsterdam are dead. Alive: Dick Van Dyke, Mary Tyler Moore, Carl Reiner, Rose Marie, Ann Guilbert (Millie- best known today probably for her role as Fran’s chain smoking grandma Yetta on THE NANNY) and Richey. Supposedly, Reiner is writing a reunion episode.
Considering that it premiered more than 31 years ago and had a large cast, MASH is doing pretty well. I think that a reunion movie would do well; I’d set it in a hotel 30 years after the war (1983-the year the show went off the air). The only cast members you wouldn’t be able to get would be McLean Stephenson (whose character died on the show anyway) and Larry Linville (who died three years ago). Even Col. Potter is still hanging around and, last time I saw him, still seemed sharp and looked the same as ever, just older. (Plot ideas: Hawkeye is now the father of 5 daughters who are making him sorry for all the Lothario ways of his past, Margaret is now a general in the regular military and knee deep in Iran-gate, Charles left medicine and became a R&B sensation, and Father Mulcahy is now Cardinal Mulcahy.)
The three principals from I DREAM OF JEANNIE are still alive- only the Bellows are dead. However, since Larry Hagman earned $7 million per minute on DALLAS, Bill Daily left show business to work as a smalltown journalist (sounds almost like a sitcom idea itself, doesn’t it?) and Barbara Eden’s navel is three inches south of where it was on the series I doubt we’ll see another reunion (besides which, the ones that they did in the 1980s sucked like a bionic Lewinsky).
Speaking of Bill Daily, all of the major and most of the minor characters from Bob Newhart are still alive. The only significant loss is Florida Friebus, who played Mrs. Bakerman in the group therapy sessions (though Carlin and Peterson are still alive).
According to the IMDB, three of the five members of the original cast of Captain Video and his Video Rangers are still alive:
Alive: Don Hastings, Richard Coogan, Fred Scott
Deceased: Jack Orisson, Bram Nossem
A 60% survival rate, which is all the more impressive since the show premiered in 1949.
Even more impressive: Don Hastings, the original Video Ranger, is not only alive, but actively working in TV, playing Dr. Robert Hughes in As the World Turns