Before the discovery of the Monica Lewinsky dress, the most well known dress in America was the one worn by Marilyn Monroe in "The Seven Year Itch". The Los Angeles Times is reporting the dress is going to auction and is expected to fetch a hefty sum:

Sometimes referred to as the "subway dress" (Monroe's character is standing on a subway grate when the updraft occurs) the ivory, pleated halter dress designed by William Travilla is considered one of the most iconic dresses in Hollywood history, and the Profiles in History auction house, which is holding the June 18 auction, estimates the value at between $1 million and $2 million. - Los Angeles Times

The auction is set for June 18th.