The director James Cameron stands out because he has only produced huge box office hits. Extremely hard to do like you said, and most artists and auteurs would be happy to have one great work they can be remembered for, even if it's amidst a dozen forgettable pieces.
Sometimes the forgettable pieces come later. In JC's case, that's Avatar 2
He's only published blockbuster hits. But I'm sure he has lots of practice films that have never seen the light of day?