I just watched the first episode of Green Acres on YouTube. TV shows had good theme songs back in the 60's. You knew what the show was about by just listening to the theme song. And they were catchy songs too.
In our family, whenever someone struggles to lift something or open a jar lid, the trombone song from Gilligan is sung to encourage/pest the one struggling. We all know it from the episode where Gilligan gets Super Strength.
Laverne and Shirley had the best "song" -- but the best opening title, ever, for any TV show was clearly "Space: 1999" (year one), which was the most epic piece of music ever for a TV show. Barry Gray rules!