I have been meaning to reply to this thread for a couple of days, mostly because it gives me a chance to rant about tea chauvinism. As I live in China, I have a few things to add to William's excellent summary as well. Of course China has the oldest tea culture, and produces thousands or at least hundreds of different teas, so it's hard to create an accurate picture in just a couple of hours or days of description.
I mentioned on my weblog meeting with a Tieguanyin salesman. I was asking him what teas he liked to drink besides TGY. He explained to me that in China, everyone drank TGY who knew anything about tea. Whenever I made any comment about any other tea, I was shut down. People in Guangzhou, Shanghai and Beijing all drink TGY unless they know nothing about tea. In my opinion, the opposite could be a more defensible position. People who don't know much about tea drink TGY. At the risk of sounding like a tea chauvinist myself, I will argue this position.
Chairman Mao identified oolong tea as the centerpeice of Chinese tea production. In areas of Fujian where the great majority of oolong was produced, there was lots of available land in agricultural areas, also oolong gardens are more productive. You use about 4 leaves of a shoot to make oolong, only one bud and maybe a couple of leaves when making green tea. I would say that Anxi and TGY received the most attention from Chairman Mao, and tea production was increased.
Today, we can find TGY all over China. It is a very famous name, and production is high enough that it is available everywhere. Modern qingxiang TGY is about halfway between an oolong and a green tea, and the taste and aroma is acceptable to a wide range of palates. For this reason, often TGY is a prestige product. Business men as well as others brag to each other about how much they paid for their TGY. This is why I say people who know nothing about tea drink TGY. If you have never heard of a tea, you won't be willing to pay a lot for it especially if you're rich because your friends won't have heard about it, therefore when you brag about how much you spent on it your friends laugh at you.
Green tea and flower tea does seem more popular in the northeast, from my limited experience there. Jiangsu and Zhejiang (the provinces to the north and south of Shanghai) are major green tea producers, so in general these types of teas are popular. Fujian and Guangdong people seem to drink a lot of oolong, but fujian produces all sorts of teas including white tea, jasmine green tea, other green teas, even a compressed oolong tea cake in Zhangzhou.
If you leave the big cities, all of these generalizations become less useful. People from smaller cities and towns usually drink their local teas. Tea is produced all over China I have read 18 provinces and municipalities and 21 provinces and municipalities, so you would be hard pressed to name an area which does not produce tea. Many local teas are not famous. Often production is low, and all of the tea is consumed locally. Often teas in less famous areas are processed to imitate famous brands and sold cheaply to retailers who will sell them at large marks ups as Xihu Longjing, etc.
Sometimes there is an intense local pride, and the local tea is seen as the best in the world. This past weekend I visited a tea garden where organic Wuniuzao is grown. The owner told me she doesn't drink anything but Wuniuzao produced in her own gardens. She admitted this was habit, she was used to drinking this tea and likes it. She also said TGY hurt her stomach. Wuniuzao is made into green tea similar to Longjing. I don't think the varietal is as good as some of the famous Longjing cultivars, but its not bad. It is also not often found outside of the city of Wenzhou. Wenzhou also has two other teas. Yandang Maofeng and Taishun Sanbeixiang. Yandang Maofeng was a tribute tea at some point, but production of this tea is so low today that it is rarely found outside of the county of Yueqing where it is produced. These local teas often fetch very high prices locally. The best batches of the most tender buds sell for over a thousand USD a pound, and are a status symbol among local business magnates. You may never drink these teas without going to the area of production and buying some personally, as the outside market is not developed, and sometimes there is no supply even if there was a market.