If the requirements are that we have to hear lyrics being sung in the theme?
1. The Greatest American Hero
2. Laverne and Shirley
3. One Day at a Time
4. Perfect Strangers
5. Happy Days
The rest of my Top Ten would be:
6. Mystery Science Theater 3000
8. Green Acres
9. The Addams Family
10. It's Garry Shandling's Show
Moonlighting just barely misses the Top Ten, coming in at #11 on my personal favorites list.