Two other films to add to the list:
I think "Some Like it Hot" (Jack Lemmon, Marilyn Monroe, B.
Wilder, I think, was the director) falls into this category.
And of course Edward D. Wood, Jr.'s classic "Glen or Glenda"
which many consider to be amongst his truly worst work
(after Plan 9 From Outer Space). Glen or Glenda is a
classic, "boy meets girl, but boy is a cross dresser and is
scared to tell girl" story (how many times do we have to see
the same plot over and over!!). The film's most moving scene
is when boy finally tells girl and she not only reassures
him that she will stay with him, but lets him wear the
angora sweater he has been drooling over! Wood made this (I
believe this was in 50's) to further the general
population's understanding of cross-dressers, which
apparently he was. Given when it was made and that he's such
a bad director to begin with, the resulting movie is
unintentionally hilarious. A must for bad movie buffs.