Star Trek has had the greatest cultural impact of any show.
Half of today's scientists grew up watching it and they inturn invented some of the things on the show. Plus first interracial kiss on television (sorta... read William Shatner's book for the info).
Billion dollar franchise (books, movies, toys, attractions, etc, etc) with legions of fans.
And let's not forget the campaign launched on NBC to bring it back from cancelled status.