For me it was the commercials for Long and Silky shampoo and conditioner in the early 70's. I still remember at the end when the model with the knee length hair would put her hands under her hair, lift it up and let it drop like a waterfall. The announcer said her last line while this magnificent hair cascaded down, "for women who never want to cut their hair"!

I wish that commercial would find it's way onto the internet! Anyone know if it is out there?