American designer Calvin Klein started his company in 1968, when Marc Jacobs was a tender 5 years old. His minimalistic, clean lines epitomized the style of the '90s, and today, his brand is one of the most recognized in the world, while his ads have become the stuff of pop-culture legend. (See: boxer briefs just peeping out of Marky Mark's jeans, Kate Moss and the Androgynous Bunch.) Klein's staying power comes partly from his understated, classic style and his emphasis on straightforward products like designer jeans. His endurance is proof that clean lines sell menswear, women's wear and ready to wear. The company is as famous for fragrances as clothes, and their names (Eternity, Obsession, Escape) embody the same melancholy simplicity as the brand's iconic marketing campaigns.