Conversation so far:
What was the highlight of Kevin Clash's career?
Kevin Clash performed and voiced Elmo on Sesame Street from 1985 to 2012.
Was Kevin Clash considered successful?
What was one of Kevin Clash's popular characters?
Kevin Clash performed and voiced Elmo on Sesame Street from 1985 to 2012.
Were there any other popular characters Kevin Clash performed as besides Elmo on Sesame Street?

Question: What was he best known for?
Self-contained rewrite: What was Kevin Clash best known for?