your thread got hijacked it seems.
HK, Shanghai, Beijing.... depends a lot on how good your languages are and how comfortable you are immersed in the "chinese experience."
HK, then Shanghai then Beijing in order of comfort for very westernized. and there's a big drop off from HK to the other two.
assuming your work will be China facing, i'd really recommend diving into Shanghai. tenure & experience on the ground, in the mainland is a precious calling card.
however, if you'd consider yourself a twinkie HK is by far the easiest (also, especially if you don't read/write well)