Shanghai is definitely the most attractive city for foreign talent. Shanghai has been ranking first in the "Amazing China - The Most Attractive Chinese Cities for ex-pats" in 6 consecutive years, organized by the Foreign Experts Bureau and voted on by foreigners. Having some teaching jobs in Shanghai are good.
Compared to other first-tier cities in China, the city is more Westernized in culture, and most foreigners find their work experience and skills easily transferable. Another reason why foreigners love the city is that it offers a wealth of Western amenities: a large number of international schools, ex-pat societies, Western restaurants, and a vibrant nightlife.