>>2815057 (OP)
Hong Kong is the obvious #1 choice, it's an atmosphere that is impossible to replicate anywhere else
I also enjoyed Shenzhen because it's ultra-modern shit but built on top of a decaying communist shithole. if you walk literally one block past the shiny light show you have favela-tier ghettos
probably most of the modernized Chinese cities would do, like Chongqing
Seoul has nice cyberpunk vibes in places but it's just ugly and depressing overall (until you get drunk on the abundant booze)
anyway cyberpunk is a meme