Mark Lenard was a true talent and really solidified the role as Sarek. He made it is even after playing the part of the Romulan Commander in Ballance of Terror.
But let's not forget his wonderful portrayal of the doomed Klingon Captain in Star Trek: The Motion Picture. It took me years, YEARS to finally discover that was actually Mark Lenard playing the part! He looked so perfect as a Klingon that even now I still can't recognize him.
I'd give anything to see his make-up process or any behind the scenes photos of him as the Klingon Captain.