Move Over, Hot 100 — These Are the Best 25 Looks in Billboard Music Awards History

Fun fact: This was Rihanna's first appearance at the Billboard Music Awards, and to commemorate the occasion, the singer wore a custom white Zac Posen minidress with gold strappy heels. Inspired by Posen's Spring 2007 collection, it featured flirty details including a pleated skirt and a dramatic plunging neckline.