Face it, everyone likes shopping. And in Beijing, many shopping centers abound such as the Baihuo Shopping Center (known for selling beauty products and shoes, among other high-end items.) The China World Trade Center is so vast that if you use up an entire day wandering through it, you still would not have visited all its shops (numbering around 200 in all).
If antique curios are what you are after, then you can visit the aptly-named Curio City (home to furniture dealers, and other retailers of antiques.) A unique retailer is the Friendship Store chain, emphasizing close ties with foreigners.