In 'Dallas', what is the name of the scheming oil baron?

In 'Succession', what is the family's last name? In 'Yellowstone', what is the name of the family that owns the ranch? Who plays John Dutton in 'Yellowstone'? In 'Downton Abbey', what is the family's surname? What was the famous cliffhanger question from 'Dallas' in 1980? In 'Happy Days', what is Fonzie's full name? Which phrase comes from 'Happy Days' and means a show has passed its peak? In 'I Love Lucy', who played Lucy Ricardo?