I was in high school when the show first started on CBS in January 1979 as a mid-season replacement for some other show. Seeing John in those skin-tight faded blue jeans would get me horny and I would have to go jack off after the show was over, in the bathroom. :D My parents probably thought it was Daisy, rather than Bo and Luke.
Tom and John were and still are ultimate j/o material. I think it is no matter how many times you seen the show, you can't argue about that sex appeal they had.