Octavia Butler.
http://www.sfwa.org/members/butler/
http://en.wikipedia.org/wiki/Octavia_Butler
http://www.business-standard.com/common/storypage.php?storyflag=y&leftnm=lmnu5&leftindx=5&lselect=2&chklogin=N&autono=216765

Clearly influential, hugely important in SF&F. First SF writer to be given a genius grant.

Everybody else has spoken about Don Knotts and the guy from Gunsmoke. And the other guy.

:(