It's a wonder: Abbey Bartlet / Betty Rizzo could have been Lois Lane in another trouser leg of time. After Roger Moore threatened to pull out of Octopussy (steady now), James "Dad Of Josh" Brolin could have been the first American Bond. De Niro could have been Sonny, Tom Selleck could have been Indy and Judy Garland could have been in Valley Of The Dolls... if she hadn't begged to be fired, that is.
Stockard Channing – Superman (1978)
James Brolin – Octopussy (1983)
Robert De Niro – The Godfather (1972)
Tom Selleck – Raiders Of The Lost Ark (1981)
Judy Garland – Valley Of The Dolls (1967)