Sun Yan Zi (Stefanie Sun) is by far my favourite chinese pop artist -- I absolutely love her. Staying with pop, I think F.I.R and Eva are pretty good, too. It's the kind of lack-of-dissonance-feel-good pop, not too ballad-like slow but not too fast-paced either with pretty melodies. F.I.R has a few rock elements thrown in here and there.
I also recently heard a Chinese punk band in Beijing which was very good. Can't remember the band name unfortunately. There are also some excellent electronic DJs in China who display good taste in their selection of mixes. The club scene (just like the modern arts scene) is pretty big and steadily growing in cities like Shanghai and Beijing, not even including Hong Kong.
I'm currently in Beijing after not having been here for 2 years and the creative potential is amazing. The circle of interest is still relatively "small" (compared to the population) but I'm hopeful that it will expand into the masses in due time. I really can't wait till the Chinese discover jazz as the Japanese did. Chinese music seems to have a faible for kitsch but looking at the modern art example, in just 3-4 years, the art community has been literally exploding in Beijing. At some of the galleries you feel like walking through a Western museum of modern art with specklessly executed and profoundly expressive paitings and sculptures - all while retaining parts of the Chinese cultural heritage through the use of distinctively Chinese symbolism, leitmotifs, etc. The same might happen to the music scene although this might still take a few years.