I would also like to see Hong Kong / Guangzhou / Taipei, which I list in order of population density.
The Taipei vibe is the best, people are well-mannered and helpful.
Hong Kong is insanely crowded, but it's better organized and more orderly than Guangzhou.
Guangzhou subways are as busy as Hong Kong in a few places that were poorly designed, mainly Tiyu Xilu Line 3 transfer under the Teem Mall, but the vibe is much different than Hong Kong and Taipei. Guangzhou feels less orderly and it used to be common for women to be constantly holding small children over trash cans in order to let them relieve themselves, which was something I never saw in Hong Kong or Taipei.
In Hong Kong, one time in 2007 a British guy got on the train right next to me probably at Admiralty, apparently getting off work as he was dressed well, and he proceeded to change into his sports clothes right there. He had concealed rugby shorts and a shirt under his business attire, so he did not show any skin, but the worst part was when he applied some very stinky medicinal cream to all his joints.
To add injury to insult, when he came on I was trying to chat up a pretty girl with long chestnut curls, but the smell of that jerk's ointment was so bad that I gave up. It was extremely rare to see a pretty white girl in China, or even any pretty Chinese girls. Thanks, pal! Besides thieves, this was the worst thing I ever saw on any of those three metro systems.
Overall, the three of them are very good. When you consider the age of HK's system, it's impressive how well it handles an unbelievable crush of people without much incident, as far as I know.
Kinda miss my Octopus card.
