Who played Ricky Ricardo in 'I Love Lucy'?

Who created '60 Minutes'? On which network did 'Doctor Who' originally air? In what year did 'Doctor Who' premiere? In which TV series is Lucy Ricardo a main character? Who played Ralph Kramden in 'The Honeymooners'? Who played Barney Fife in 'The Andy Griffith Show'? Who played Opie Taylor in 'The Andy Griffith Show'? In which TV series is Opie Taylor a main character?