Burt Lancaster or Marlon Brando?
Marlon Brando is one of the most iconic faces to come out of the film industry back in his day. It's impossible to imagine anyone else other than Brando as Con Corleone, but that was almost the case! At it's initial inception, the film's rights were almost secured by Burt Lancaster and his group of filmmakers.
Lost Lancaster
Lancaster was really gunning for the role of Don Corleone once the novel started making its rounds. He was beaten out of the rights by another group of filmmakers, so his dreams of becoming the crime boss were over. Brando was probably better suited for the role anyhow, and Lancaster did just fine without this role!