Best Northern Chinese food in Flushing
I think Peter has answered it all. (I now prefer the term Manchurian over Northeast or Dongbei). Any good Manchurian restaurant will have a wide variety of dumplings, particularly with pickled cabbage.
Here's more on Jiang Li and Rifu/Yanbian:
Rifu and Yanbian:
First of all, the spots you mention are all Northeastern Chinese and Northeast China covers a large area that includes three provinces and five optional Inner Mongolian prefectures (http://en.wikipedia.org/wiki/Northeast_China), so choosing dishes across this realm might not necessarily be helpful unless we can deduce what specific cuisine each restaurant is attempting to produce. Or possibly I am wrong and this is a valid endeavor.
Either way, maybe someone has this information? Otherwise perhaps it would be best to focus on favorite dishes per restaurant. Any thoughts?
Wenzhou is a Southeastern city.
Some other spots are Jiang Li (http://flic.kr/s/aHsjumfaUg) across from Lao Dong Bei on Kissena, and Spicy Road (http://flic.kr/s/aHsjuwYU7E), down by the Queens Botanical Garden on Main St, which has since changed its Chinese name from Tianjin Beijing to Four Seas or somesuch (四海居).
One wrinkle to consider is the fact that there are at least 10 and possibly 20 or more Yanbian restaurants in Flushing. Yanbian is a Korean Autonomous Prefecture in Jilin province, which is one of three provinces mentioned above that comprise Northeast China. I'm not sure if you wanted to include these in your survey or not.