Among the most revered, Marlon Brando, who brought the powerful Don Vito Corleone to life, passed away in 2004 due to respiratory failure at the age of 80. His groundbreaking portrayal remains a defining moment in film history. Richard Castellano, who played the jovial Peter Clemenza, died from a heart attack in 1988, while Al Martino, the beloved Johnny Fontaine, succumbed to a heart attack in 2009 at 82.