I just watched Blue Lagoon for the first time. It's hard to believe that it was controversial when it came out--the thing could be broadcast on the Hallmark Channel without raising many eyebrows. A modern teenager would probably be more fascinated by the way Brooke Shields' hair stays firmly planted over her breasts whenever she goes topless than the nudity, which is more hinted at than actual.
The really fascinating thing about the film is that it basically has no plot. The elevator pitch for Blue Lagoon would be "You love the montage scene where the teenagers fall in love, right? What if that were an entire movie?" It's strangely compelling, but only if you watch it the way I did--with a book.