Gigi! One of the best films featuring Louis Jourdan as Gaston and Leslie Caron as Gigi. Gigi is being trained as a Parisian courtesan by her grandmother but instead falls in love with Gaston, a playboy from the Parisian upper class, and he with her.
The final "courtesan" dress in Gigi is just spectacular. It's way too simplistic for the era, but it fits the character, which is more important, in the end. Plus, I adore the half moon hair pin (which you unfortunately can't see in this publicity photo).