Ricardo Montalban will always be Khan to me
Despite that he isn't only Khan. I never missed Fantasy Island and when I watched that he WAS Mr. Roarke. The two characters were so different that if you eliminated the different costumes you would still know who he was playing just by voice and gesture.
He could give Mr. Roarke a hint of darkness when called for without making him evil and he gave Khan a human heart so that neither was a cardboard cut out of a hero or a villain. He deserved more than his one Emmy award.