Designers often draw on the past - be it famous people or an era of fashion - to help inspire the looks for their current collections. While at New York Fashion Week, we made it our mission to find out the favorite fashion decades of some of the industry's biggest celebrities and designers. From Prabal Gurung to Olivia Palermo and more, find out who among this fashion crowd has an affinity for the Roaring '20s, '70s disco, and beyond. On Allison McNamara: BCBG Max Azria jacket, Zara blouse.