This one is hard to decide, but using the true meaning of the phrase, when some babe flashes her stuff for no idenfitiable reason (i.e. can't count pre-sex scenes),
I'd have to go with the scene in "How to Make a Monster" when Julie Strain was put into the robot body and the tech geeks asked her to jump up and down to "calibrate the sensors". Fun stuff.
Any others?
"Star Slammer" (http://us.imdb.com/Title?0087945) has probably the most totally un-neccessary shot(s) I've ever seen.
Hybrid (http://www.badmovies.org/movies/hybrid/), all the way. It even qualifies as a totally random lesbian shower scene.
I can only think of worst. It was in Leprechaun 4. The one chick in the whole movie we didn't want to see, we saw and the hot blond chick and the home improvement girl kept them covered. There is no justice.
Airplane!
The scene where they first encounter turbulence, first they show a shot of jello, then a shot of a shirted woman, then a shot of her shirtless. Completely gratuitious, and I believe they were trying to make it gratuitious.
Is that Airplane 1 or 2? I remember the gratuitous scene in 1, but remember the jello scene in 2, which I don't believe had nudity [other than an earlier scene involving the X-ray machine.]
Darn, now I gotta watch them again to make sure.
It was #1. I remember because even my grandmother (think sweet little old lady/ proper English lady) got a kick out of it. Maybe the jello was only in #2.
Not sure if this counts, but in AIRPLANE! after the passengers panic a topless woman just runs up to the camera! Very gratuitous, but very funny as well.
Used Cars - While filming their commercial the model gets her dress ripped off.
WHEN NATURE CALLS--the Van Wapishes pass a sign that says BEAR LEFT, then one that says BEAR RIGHT, then one that says BARE BREASTS, with a topless woman standing by it, waving.
I still think I should rewatch those AIRPLANE movies, though....just to be sure. I am nothing if not exacting in my research on this topic.
I'm gonna go with BLACK ROSES, that dumb metal horror movie from the 80's. There's a scene where a girl looks at herself in the mirror and massages her bare breasts for a minute or so. Completely gratuitous, but what makes it doubly so is that the camera never pans up to her face. Who is she and what does she have to do with the plot? We'll never know.
Either Linda Hamilton in "King Kong II" (She rushes to get dressed after having sex with whoever starred in that dreck and we see her boobs for a second) or Janine Theriault in "Bleeders". She is brutally murdered in the first half of the movie, and then almost at the end of it a character founds her corpse hanged upside down and her t-shirt has slipped all the way down.
I don't think there is any such thing as a gratuitous breast shot.
Each breast shot is carefully selected and adds depth to the characters and meaning to the film. I have never seen a better example of artistic expression or dedication to the craft of filmmaking than a well-placed breast shot.
I think we should change the topic to "most gratuitous lack of breast shots."