China eating, especially Nanjing
You must try the ShengJianBao... down the street from NanJingDaXue... there is a little row of shops that all serve amazing food, but you will see a long line (at any time of day) in front of this one particular shop that sells the best shengjianbao... kind of like a xiaolongbao but fried. The thing that makes their's particularly delicious is they use the thin skins just like xiaolongbao, as opposed to the typical bready "bao" skins usually used. Most locals/cabbies will know the spot.
I think it's because people don't go to Nanjing much, except for day trips. I've read that Nanjing doesn't have much of a cuisine of its own due to its crossroads location and historic instabliity (it was always being over-run and occupied by one faction or another), but has pretty much adopted Shanghainese/Jiangnan cuisine as its favorite. There are some true local specialties (mostly duck-ish), however, and these two pages may be helpful:
If you hit Shanghai first, you can get a preview of some Nanjing offerings at one of my favorite spots, Xiao Jinling Restaurant on the Yunnan Nan Lu food street. Go for the salted duck and the tofu/bean thread soup!