In response to the thread on miscast actors, how about we consider those films where the actor could not have been bettered in the role. Not just a role where the actor did what was needed or “made it their own” but one where the role seemed to answer something in their soul. One film per actor please and if you want to dethrone another poster's choice for that particular actor, be prepared to make your case why! Some that occur to me: Tom Cruise in The Firm. From arrogant charmer to scared schoolboy to resolute hero, this was the character that had in spades everything that the Cruiser would rely on through the rest of his career, and it also inaugurated the “Tom Cruise Running” meme. Peter Sellers in Being There. Most comedians can play the melancholy clown (& many do!) but the result would be a very downbeat film. As Chance The Gardener Sellars embodied a mixture of wisdom, innocence, sadness and purity unlike anything else on celluloid. Al Pacino in The Godfather. Michael Corleone's journey from reserved, slightly shy war hero to secretive, vengeful don is at the heart of the first two movies and Pacino can't be bettered. I think he became a terrible ham in his later career, but Coppola harnessed his energy perfectly in this role. Henry Fonda in Once Upon A Time In the West. This is an example that my mother likes to give. Fonda was known as a cool heroic type before this, but the role of merciless antagonist seemed to make a virtue out of his coldness. His entrance in the film is one of the great screen moments: even as a physical presence he embodied the role, despite being cast against type. Peter Falk as Columbo. No explanation needed. The only actor I could even imagine taking over the role is Sam Rockwell, but in any case he is now too old to do so. Kate Hudson in Almost Famous. When I saw Kate Hudson in the role of Penny Lane I thought that she was a wonderful actress who would have an amazing career, but it turned out that she was just perfectly cast for that one movie. The mixture of teenage grandiloquence, naivety, sexual magnetism and youthful selfishness were ideal for her, and the camera loved her in the role.