Again, highest percentage goes to Wanted Dead or Alive* (1 cast member, Steve McQueen, deceased) and also to Have Gun Will Travel (one cast member, Richard Boone, deceased), both with 100% of the cast dead. HGWT ran until 1963, so Boone is ahead.
Rod Serling’s Night Gallery also has a 100% death rate for the only recurring part – Rod Serling. The show ran in 1970.
But the true champion has to be Alfred Hitchcock Presents. When it ran new episodes in 1985, the only regularly appearing character (Alfred Hitchcock) had been dead for five years.
From the UK, Dad’s Army consisted of 7 men in the Home Guard in a show that ran from 1968 to 1977. By 1984, 5 of the 7 were dead, but the other 2 are still with us in 2003. There was an eighth character who was not in the “army” (he was an air raid warden), who is also still alive.
Not only did Jennifer O’Neill shoot herself with a .38, she has survived being dropped to the floor by John Wayne, thrown from a horse, involved in an auto accident, and more.