Flock of Seagulls
http://myggm.org/wp-content/uploads/2013/06/FlockOfSeagulls2.jpg
I can’t link a photo on this phone, but I’m going with the pic of the Afghan girl with the penetrating green eyes.
If it was a worldwide challenge I would put forward a photo of the Berlin Wall coming down, but figure that may not be well known enought in the U.S. So I suggest a photo of 1989 Madonna.
That’s exactly what I was thinking. Either that or some image of Grace Jones with heavy makeup and pointy hair. Like this.
Oh, and I saw a picture of Pee Wee Herman while looking for Grace, so there’s that.
No writing? Damn, that disqualifies the ZIP ZAP RAP album cover. Sorry, Devastatin’ Dave.
First thing I thought of.
Don’t know why you’d think the fall of the Berlin Wall is unknown in the US.
Leg warmers, baby! And the hair!
Although they broke up in the early 80s, I think the Police would still qualify.
As far as capturing how the styles were: Any John Hughes movie poster but I think Pretty in Pink works best, perhaps next to one from House Party.
These two work:
I’m sure it’s known, but poll a group of 100,000 Americans and be sure they would all know when it fell? Given it happened around the turn of the 90s it could very easily be placed in that decade not the 80s.
A lady playing tennis (I could be off by a decade though.)
I was going to go with the most purchased poster ever. But then I realized it was from 76. (Damn I’m old.)
After those red leather jackets and big blond hair, once I could concentrate, this was the first one I could think of:
Well, wait a minute:
I forgot 20 Minute Workout
Now, that’s what I call a tennis bum! 
James Mav listed the top two posters in the 80s as 1) the tennis lady and 2) the lamborghini countach. I will add the shuttle columbia and the F-15 fighter jet.