I'm not a shopper, but I loved the silk road, virtually all a tourist would want. The shopkeepers are very pushy to sell you anything. Don't fall for this. I bought some brand name gear.
If I went back to Beijing, my time would now be spent shopping, with some time visiting places our tour didn't show us. Wangfujing St is very good as with some of the side streets for a tourist to do some shopping.