Hong Kong and Shanghai - top 3
The ubiquitious Shanghai soup dumplings, of course. Made well in lots of little places.
And "chain" or not, we loved South Beauty - in the large shopping complex in Pudong or the very lovely location in the French Concession -- for sichuan - an artful cuisine and easy access to the pictured menu for beginners. Build a wonderful meal and play the exquisite, inscrutible "hotness" of the flavorings off the cooling sweetness of the breads. They are opening another in the historic Bund area as well.
Did not like Shanghai Uncle and found Cantonese offerings even at the best establishments bland after our seduction by "real" sichuan cuisine.