Garry Marshall is responsible for one of the decade’s best sitcoms, The Odd Couple, an adaptation of the hit play and film, with Tony Randall and Jack Klugman locked in one of the great comic duets. Unlike Lear and MTM’s shows, The Odd Couple is timeless, a throwback to the high-concept sitcoms of the ’60s. Oscar and Felix, the uptight snob and the messy slob, are such a perfect duality that the show doesn’t need other characters. In fact, it suffers when there are other characters on screen. Yet the series works because it doesn’t bother with timeliness or social commentary. It just produces the funniest experience it can. The Odd Couple is a great show that doesn’t fit comfortably within any of the movements that dominated the sitcoms of the decade. It’s a ’70s sitcom only because it was produced in the ’70s.

http://www.avclub.com/articles/70s-sitcoms,45254/