Jonny, I forgot to mention another of my all-time favorite Duke films, The Searchers. That performance should have earned him an Oscar. Jeff Hunter was also excellent in that film, and should have gotten the best supporting actor Oscar for that role. I don't know who and what won the Oscars for 1956, but Duke and Hunter deserved the awards.
Best picture for 1955 (awarded in 1956) was "Around The World In 80 Days". Wow. It even beat "The Ten Commandments".