I'll add Lee Strasberg to that list. His portrayal of Hyman Roth was just right.
His lecture to Michael Corleone, "This is the business we've chosen", is a masterpiece of monologue. I realize that former Ronald Reagan speechwriter Peggy Noonan has lost her bearing but her analysis of Roth's speech, "as he stood, weak and furious, before cold-eyed Michael Corleone", is a worthwhile read, a portion of which is excerpted here:
It is simple, unadorned, direct, declarative. There isn't anything in it that is "eloquent," and yet taken as a whole it is deeply eloquent: It tells you something big in an unforgettable way. There is in it no obvious, signaled rhythm, and yet if you read it aloud you will find in it the beautiful, unconscious rhythm of concentrated human speech. There are no phrases that seem to attempt to conjure up pictures, and yet when you hear it you imagine a Moe Green and see the dusty nothingness of early Las Vegas.
It is simplicity that gives the speech its power. Each word means something and each seems to inevitably follow the word that precedes it and summon the word that follows. And so a kind of propulsion is created: It moves forward, and with good speed.