I can only speak for Hong Kong. The place to go for cameras is Tsim Sha Tsui (aka TST) area. If you walk along Nathan Road towards the water end and check out all the streets leading to it, there are many shops to shop from.
One think to watch out is that there are 2 types of equipment being sold in HK. One type is exclusively for HK sales and the price is relatively higher and the other is the Japanese imports i.e. grey market stuff. It is very easy to spot these as all the printed material is in Japanese. The grey market stuff is even cheaper.
There was a nice little shop just off Nathan Rd that dealt only Nikon stuff and was very well stocked when I was there 10 years ago. So I assume that shop is still there :-) I can't remember but it is one of those streets that lead to Nathan Rd from the right hand side like Mody Rd., Cameron Rd. or the one after Salisbury (before mody).
hope it helps...
edit: just checked on the map and I remembered: Middle road. Go there, the store is on the right hand side before the Multi Storey Car part. There are many stores on that road to choose from but that little one is the place. I still use the lenses I picked up from that store (Nikon 35-70 f2.8 AF-D, Nikon 500mm f8 Mirror, Nikon 50mm f1.4)