I'm with you about Leo - he *still* looks like a kid to me.
One I can't explain even though I'm afflicted by it, is why Sam Waterston is attractive. He hasn't got what you'd call the usual semetrical features that qualify for "good looks". In his case, I think it must certainly be force of personality (which in his case *is* attractive). Now, I recently saw a picture of his son -- good looking.