I'm an oldfag and I remember the glory days of the late 70s and early 80s when quite a lot of movies (even family films) would often include a gratuitous tit shot. This, of course, was to encourage repeat viewings and sales of VHS copies. Examples which I rember include Trading Places when Jamie Lee Curtis takes her top off for no good reason, The Man With Two Brains and Airplane! Probably the most gratuitous of recent times is Halle Berry in Swordfish, although frankly they were a bit underwhelming.
They seem to be dying out as porn and sex tapes are so easily available. What is your best gratuitous tit shot?