Any of the live/fresh foods. Some places will have the live crabs & shellfish, but the better places will have larger live fish, maybe even eels if you're lucky. You can freeze unagi & it's just fine thawed & reheated. Squid tubes, tobiko, uni, etc...
I'd have a look at lots of different recipes & make a shopping list for the various ingredients for those recipes. You might have need at some point for those difficult to find anywhere else items like the shrimp paste or various spices or condiments.
The one thing I wanted for years was gai laan, but could never find it. It's also known as "Chinese broccoli," or "Chinese kale." IMHO, this is the tastiest of all green veggies on the planet when stir-fried with a little dark sesame oil, garlic & oyster sauce. I used to ask for it everywhere & the best they could come up with was baby bok choy. I had to grow my own to get real gai laan; if you can get that, you'll not be disappointed. There are several different varieties, here's a link that'll show you some pics & tell you a bit about them:
http://www.evergreenseeds.com/chinkalgail.html
I'd also look for gobo (burdock root), chrysanthemum, lychees, various hard to find herbs & spices; maybe not so hard to find, but you might get them fresher & cheaper. Here's a link to various Asian fruit you might find useful:
http://www.frangipani.com/wordpress/thai-fruits/#.UojR6cSkrfc
Any kitchen implements you may need for Asian style cooking, woks, steamers, bamboo & brass long handled strainers, serving plates & bowls, teapots/tea sets, and don't forget the tea.
Regards, GF.