My favorite movie with nudity, which isn't the same as what was asked, I know, is Prospero's Books. It was one of Gielgud's last movies--a fairly faithful version of The Tempest with him as Prospero.
The thing is, Peter Greenaway did it. As in "The Cook, The Thief, His Wife and Her Lover", "Two Noughts and a Zed", and of course "The Pillow Book" Peter Greenaway. So there was Flesh.
What he did was actually quite original. To replicate the feeling that a Jacobean audience must have had watching a play about a magical island where the air teemed with spirits, he put the actors in period costumes, but had a constant background scrum of naked writhing bodies, of ALL shapes and sizes, which NO ONE NOTICED. EVER. They were a manifestation of a place thick with invisible magical beings.