Many things people say about modern fashion (Things are changing so fast! The skirts are scandalous! That doesn't even flatter the body!) become even sillier when you look at pictures of women in the 1920s. Jazz Age Beauties: The Lost Collection of Ziegfeld Photographer Alfred Cheney Johnston is full of women in dramatic makeup and shocking cuts only a few years removed from the Gibson Girl image.
Go even edgier with street shots of regular people in We're Desperate: The Punk Rock Photography of Jim Jocoy, SF/LA 1978-1980. Excellent for anyone wanting to by-pass the mall bastardization and explore the fashion roots of the punk movement.
For the glamorous vintage lover on many of your shopping lists, Movie Star Portraits of the Forties is a goldmine of style and class. In the same style Lillian Bassman: Women is a retrospective of images shot by Bassman primarily in the 50s.