Growing up I enjoyed tv theme songs especially ones that let you know what the show was about. There were many; Gilligan’s Island, The Brady Bunch, The Partridge Family, My Mother the Car, The Beverly Hillbillies, The Flintstones (actually most of the Hanna Barbara cartoon's theme songs did this)

What other show's theme songs explained their show and which one would you think was the last on to do this.

Diff'rent Strokes.

"Fresh Prince of Bel-Air" is the most recent one that comes to my mind.

Some shows (My Two Dads and The Odd Couple to name two) don’t explain the premise in song lyrics but in voiceover in the opening credits.

Green Acres

I was going to add The Many Loves of Dobie Gillis since in the beginning he was always chasing a girl. But the show lost that focus and was only a part of the storyline.