I like your list Bro Lala and Cookie... yum!!Last year and year before, Ginza had a lot of Japanese girls.
There are more Chinese girls now. The quality is same though; nothing has changed.
But in terms of service, this is what I have noticed in Ginza:
Japanese girls: They are more genuine; They will treat you like their boy friend. This is my personal opinion but Japanese girls seem to have hedonistic tendencies. I had one girl who writhe like crazy just from mere touch.
Chinese girls: They are more service-oriented; They will give you the best service. They make sure you are satisfied by the end of the session.
Chinese girl "Shella" surprisingly was more like a Japanese courtesan in her service rather than Chinese.
Korean girls: Same as Chinese.
As for your question regarding most beautiful. Here are my favorites according to looks:
1) Chinese Lala (Looks like Taiwanese actress Shu Qi )
2) Thai Alin
3) Chinese Cookie (Chinese version of Rachael Leigh Cook and Minka Kelly)
4) Korean Angela (Straight out of K-Pop video)
5) Chinese Sophia (Sultry look)
Favorites according to service:
1) Chinese Lala
2) Korean Angela
3) Thai Alin
4) Chinese Sophia
5) Chinese Cookie
There are way too many girls in Ginza that I haven't seen. So these are just from the list of few I have seen.