Which TV sitcom had a theme song which opened with the line, "People Let me tell you 'bout my best friend"?

The 1969 - 1972 TV sitcom, The Courtship of Eddie’s Father was a TV show about a widower, Tom Corbett (Bill Bixby) and his son, Eddie (Brandon Cruz). Eddie is a boy who believes his father should get married. He finds that he needs to manipulate many situations surrounding the women in his father's life. This television series debuted on September 17, 1969; the last of the show’s 73 episodes was broadcast on March 1, 1972.

The television show’s theme song, “Best Friend”, was written and performed by singer/songwriter Harry Nilsson (aka Nilsson). The lyrics for “Best Friend” start and proceed as follows:

• People let me tell you ’bout my best friend,
  
• He’s a warm-hearted person who’ll love me ’til the end.
  
• People let me tell you bout my best friend,
  
• He’s a one boy cuddly toy — my up, my down, my pride and joy.
  
• People let me tell you ’bout him — he’s so much fun,
  
• Whether we’re talkin’ man to man or whether we’re talking son to son.
  
• ‘Cause he’s my best friend.
  
• Yes, he’s my best friend…