These three places have different flavor~ Wanfujing is mainly for travelers, where you could find some local products and time-honored shops. Xidan is much fashion and is fond of many young ladies. You could find some fashion and well-known brands here, such as H&M, Levi's, Zara... Yashou in Sanlitun is a clothing market, just like the famous Silk Market. So, you could purchase some clothes or shoes at very resonable price.. There is a wholesale market near Beijing Zoo, stuff there is low-priced. Remember to bargain~