Peter Sellers: He was equally great in all of his films, but 'Dr. Strangelove' is #1 without a doubt.
Marlon Brando: It has to be 'On the Waterfront', because you can see a true actor. Unlike in 'The Godfather' or anything from the 1960's onward, he wasn't playing a character, he was the character. His performance in that film was stunning.
Robert De Niro: I'm partial to his comedic performances, "Analyze This", "Meet the Parents", "King of Comedy". They were great roles for such a serious persona, but his best performance was as the Vietnam vet, Travis Bickle in 'Taxi Driver'.
Gary Oldman: I liked his take on Lee Harvey Oswald in "JFK". It was a small role, so if we're talking about leading roles I would vote for "Sid and Nancy".
Christopher Walken: Who can forget his small, hilarious parts in "Annie Hall" and "Pulp Fiction"? Those were showshoppers! Again, focusing on lead roles I'd say that 'The Deer Hunter' gave him the most to work with and he did an amazing job.
Clint Eastwood: He plays one of two characters in all of his films, so I have to choose between his good guy roles and his bad guy roles. I like him as the good guy so I'll say "Dirty Harry", "In the Line of Fire", and "Play Misty For Me" are among the parts that collectively represent one ultimate role.
Robert Carlyle: I'll never forget Trainspotting, due solely to his role.
Morgan Freeman: "The Shawshank Redemption".
Samuel l. Jackson: Again, one of those actors who has been typecasted in the same role for years. I'd say his role of Ordell Robbie in "Jackie Brown" was his juiciest.
Steve Buscemi: "Fargo"
I also liked him on Nick of Time
