Dump a teenager in Siam Square with a few thousand baht and she'll stay occupied for the rest of the week! Siam Square is the place to shop in Bangkok; the small sois of Siam Square have dozens of small designer boutiques. MBK Center and Siam Center are the most popular shopping malls, as they sell fashion well below Western rates. Siam Paragon, EmQuartier in Sukhumvit, ICONSIAM in Khlong San, Central Embassy in Phloen Chit and the shopping plazas at Ratchaprasong feel even larger, but are much quieter, as most local Thais cannot afford the Guccis and Louis Vuittons on sale there. Ladies will also feel well at home in the Emporium next to EmQuartier.
Just take a few steps out of your hotel and Bangkok feels like a huge street market. Sukhumvit has the usual souvenirs, T-shirts and other tacky tourist junk. Browsing Khao San Road's roadside stalls is particularly good for clothing and accessories, many of them for a bargain. While many of these stalls still cater to the traditional hippie crowd, they have been slowly gentrifying to appeal to a broader audience. The nearby Banglamphu Market sells cheap knock-offs of everything, just like the night markets in Silom and Rattanakosin.
In the weekends, the Chatuchak Weekend Market in Phahonyothin is a must as its 8,000 stalls together form the largest market in Southeast Asia. Shoppers can buy just about everything from clothing to potted plants and everything in between — it is a paradise for browsers and bargain-hunters alike. A weekday alternative is Pratunam, one of the city's renowned garment markets. Clothes shopping here goes on wholesale, and you're even cheaper off if you buy in bulk. At Pantip Plaza you can buy computer-related stuff from branded laptops to pirated DVDs.
Yaowarat and Phahurat give a more authentic experience, although many stores sell the cheap teen accessories found elsewhere as well. Just sitting at a plastic chair and watching daily commerce evolve is a fun activity in itself. Phahurat is the best destination for fabrics, available in all colours and sizes. Pak Khlong Talat is a surprisingly fun wholesale market for cut flowers and vegetables. If you're a morning person, visit it around 03:00, when new flowers from upcountry arrive and the marketplace is beautifully illuminated.
Thonburi, being one of the least developed areas of Bangkok, is the best place to experience what the city used to be like. A must is the weekends-only Taling Chan Floating Market, which feels at least somewhat authentic as it blends a rural market with the canal side way of life. Wang Lang Market is an undiscovered gem with strictly local prices. The other side of the river, Rattanakosin, has everything a good Buddhist would need, be it amulets, monk bowls or human-sized Buddha statues.
For antiques, Silom is the place to go, as most potential buyers stay there in expensive hotels. River City in Yaowarat is the largest antique mall of the city, and priced to match. Gold and gems are popular buys, but be careful: know what you're looking for such as quality of workmanship and gold/stones and what something like it costs back home. If possible by prior research, not street vendor recommendation, go to respected jewellers, and polish your bargaining skills. Many tourists buy worthless pieces of cut glass believing it to be valuable gems. Others get jewellery or gems at unjustified costs. Never let tuk-tuk drivers take you to a gem/jewelry store; more often than not, you'll be ripped off and they're getting a commission for taking you there. The same advice applies to tailoring shops; you can get a custom-made suit at low prices, but you have to know where to go, as many tailors provide bad quality — see the sidebar for advice on finding a good tailor.
Browsing second hand English-language books can best be done on Khao San Road. For new releases, there are plenty of chain stores in shopping plazas, including Asia Books, B2S, Bookazine and Kinokuniya. There's a particularly wide array of books on Asian culture and history; some have a good selection of foreign newspapers and magazines as well.