Monroe and Madonna.
Both women are sex symbols, but what separates the "M" ladies from the scores of bombshells dropped on our culture every year is that they are both blessed with tremendous talent.
Not talent in the sense of Mozart or Olivier (that's genius, something else entirely), but rather an ability to make us like them.
The comic charm of both women lets us fall in love without begging us to take them seriously. Our acceptance of them in whatever roles they play, in song or on screen, comes as naturally as the welcome discovery of a new friend.