Shanghai is crowded, loud, grey, and ugly. It's a lot like New York: very trend-conscious, busy busy busy, everyone rushing everywhere, no time to look you in the eye or have a friendly conversation. Sometimes even Northern Chinese don't get far in the shops if they don't speak Shanghai dialect. That said, the weird Old World European flavor of The Bund is oddly appealing. Shanghai has always been China's most metropolitan city, and so it's popular with a lot of foreigners. Maybe that's why Chengdu is my favorite city in China. Oh well, I have a Shanghai Hard Rock Cafe shirt anyway. :p

Okay, let me modify my opinion somewhat. Every day I was in Shanghai, it was hot, grey and drizzly. If I come back to Shanghai in the sun, maybe I'll feel differently. I did feel that it has a lot of the worst traits of Chinese and European mega-cities put together, but that combination is what most people love about the place. (Though a lot of Chinese strongly prefer either the North or the South...) And for the record, we just ventured into the HRC because it was right across from our hotel (the JC Mandarin) long enough to get a couple t-shirts--the entrance was full of hookers and trendoid Chinese/tourists.

Anyway, if you go to China, you certainly shouldn't miss Shanghai. Lots of the more recent history of China there, and a truly unique feel to the place. Just don't let it be your only experience with China, just as Tokyo shouldn't be your only impression of Japan.