The Incredible Hulk, and The Courtship of Eddie's Father. Both starring Bill Bixby coincidentally enough, although I don't think he had anything to do with the theme songs.
EDIT: Ooo, and Lost in Space. That one was cool too. This isn't a good topic for a poll, there are too many.
[ June 20, 2002, 21:31: Message edited by: geoschmo ]