Shanghai divides at the river. Puxi on the west bank is the older city where most of the character lives; Pudong on the east is the skyline you have seen in photographs. Most visitors are happier staying in Puxi and looking at Pudong.
The former French Concession#
Tree-lined streets, low buildings, independent shops, cafés and small restaurants. It is the most pleasant part of the city simply to walk around, and walking is how Shanghai rewards you.
Spread across parts of Xuhui and Huangpu, well served by Lines 1, 7, 10 and 12. This is the base to pick if you want to like the city rather than only tick it off.
The Bund and Huangpu#
The waterfront and the streets behind it, including Nanjing Road and the People's Square area. You are among the landmark buildings, with the classic view across the water, and transport in every direction from People's Square, where Lines 1, 2 and 8 meet.
Busier and more touristed. Convenient in a way that costs some atmosphere.
Jing'an#
North of the Concession, around the temple of the same name. A good middle option — central, well connected on Lines 2 and 7, with plenty of eating nearby and less crowding than the Bund.
Lujiazui and Pudong#
Under the towers on the east bank. Big international hotels, high floors, spectacular views. Line 2 puts you back in Puxi quickly.
The area is built at motorway scale and has little street life. Excellent for a view and a business trip, less good for wandering out to find dinner.
Near Hongqiao#
Worth considering only if you arrive late and leave early by high-speed rail, since the station and airport share a site. Otherwise it is too far west.
For sights, day trips and how long to stay, see the Shanghai destination guide, and things to do in Shanghai for each sight's Chinese address and metro stop. Shanghai nightlife maps the going-out districts against these neighbourhoods.