In vancouver, if you are in downtown, go to the hyatt hotel (theres only one), theres a Chinese resturant called Victoria Seafood Chinese Restrurant, pretty high end Chinese food and great dim sim, owned by big restrurant chain back in HK, as authentic as it gets! I go there every sunday with my family.
If you want to be surrounded by TENS OF THOUSANDS of Chinese people (mostly from HK), go to Richmond, it is about 15-20 mins north away from the border crossing and you will find basically everything you will find in HK (restrurants, malls, shops) and tons of nice cars (bmw, merc, porsche, etc) driven by mostly again HK people...you can spend days, even months without speaking a word of English in Richmond
