Depends on what you want to buy. CDs? Books? Magazines? DVDs? From the top of my head, there's Thaimegamart (http://thaimegamart.com/) and Pinklemon (http://www.pinklemon.com/default.asp). However, Pinklemon is all in Thai.
AFN (Asianfuse network)
aymieluvsyu637
there's http://imagine-direct.com/ it's kind of like ethai
aymieluvsyu637
no problem.. may I ask what are you trying to purchase?