"Mr. Smith Goes to Washington" (1939)
Jimmy Stewart plays Jefferson Smith, a wide-eyed optimist who is appointed to fill a seat in the United States Senate. The beautiful and brassy Jean Arthur plays Clarissa Saunders, a cynical Washington insider who can't believe she's stuck working for an overgrown Boy Scout like Smith.
Over time, however, Smith's belief in the American Dream melts Clarissa's heart, and she puts her entire career on the line for him. Though Jimmy Stewart and Jean Arthur don't even kiss on screen, Clarissa's love for Jeff is one of the film's high points.