CentralWorld - The largest mixed-use complex in the heart of Bangkok. The project comprises an area of more than 830,000 sqm, whith over 550,000 sqm contributing to CentralWorld Shopping Complex, the largest lifestyle shopping complex in Southeast Asia and Hong Kong. that you’ll find brands that are trendy and generally wallet- friendly. Inside its mammoth-size structure, there is everything you need to enjoy your day: delicious restaurants, 500+ shops, a world class cinema as well as occasional exciting events.

Chatuchak Market- Overflowing with souvenirs, food, clothes, art...  It’s a great experience even for non-shoppers, and really easy to get to on the Skytrain. Open on weekends only. Next to BTS Mochit station. Very interesting, but it can be very hot and crowded.

Suan-Lum Night Bazaar- Similar to Chatuchak Market with souvenirs, local food and beer. Open daily from late afternoon until midnight. Next to MRT Lumphini station, Great place to eat and hang out in at night.

Siam Paragon- A new, upmarket mega mall with a department store and many high end boutiques and shops. This is a family destination with something for everyone - Siam Ocean World at the basement should keep the kids busy while the serious shopper is at work.  Exit at BTS Siam Station which leads to level 2 of this mall. Connected with other shopping mall : Discovery, Siam Centre and MBK. So if you want to have some serious shopping, this is the perfect place.

Siam Square- Just opposite Siam Centre, start with Soi 5 end with Soi 2. Endless little shops of local designers. Goodies sold from great dresses to vintage bags. Shopping heaven for a budget!

Mah Boon Krong - MBK- A popular mall with hundreds of small shops offering low to mid priced casualwear, shoes, bags, mobile phones etc. etc. Linked to BTS National Stadium Station, or a short walk from BTS Siam Station.

Platinum Fashion Mall - A New mall, similar to MBK, but without the need to bargain hard, and with lots of good choices.  The Food court in top floor really good. There are 'retail price' (if you buy only 1 pc or 2) or 'wholesale price' (if you buy 3 pcs or more), which is a lot cheaper. Near Pratunam Area.  Some highlights include a baby & kids clothing store, "O'Fin," near the escalator, and a unique store selling only "white clothes" near the 'Black Canyon Coffee'

Panthip Plaza - The place to go shopping for computer software and hardware in Bangkok. Hundreds of small stands and shops on four levels are in this multistory complex. Everything from outdated computer parts to new Macs.

Baan Baat Community between Chinatown and Golden Mount - a small family community still making monks begging bowls by hand. Probably one of the last places that do, a practice nearly wiped out by cheap Chinese machine bowls. A bit hard to find tucked down an alleyway off Boriphat Road. The bowls are made from eight separate pieces of steel representing the eight spokes of the wheel of dharma, and the eightfold path of Buddhism. Can be deafening but you can buy a bowl for about 700 Baht and be complacent in knowing that you own a genuine piece of real Bangkok history. When you hit the side of the bowl it resonates, as each bowl is hand made they all have a different resonance.

Personal Shopping Assistant
Bangkok has Personal Shopping Assistants, too.  Could be very useful, if you are looking for something off the beaten track or stuff a bit more difficult to find like Thai furniture. Also, there are two prices for almost everything in Thailand: one for Thai people; one for Farang.