San Francisco's Chinatown is a vibrant community of colorful streets and alleyways, strange smells and tacky souvenirs. It's a busy, crowded place with great restaurants and offbeat attractions.
Stockton Street is the heart of the community, where you'll find a colorful morning produce market and authentic Chinese shops. I loved shopping there; it's one of the best Chinatowns outside of Asia I have to assume. :-)
The restaurants are good with mostly inexpensive food. McDonalds, with its sign written in Chinese, even served noodles.
There are many little shops thru-out. The main source of goods sold are souviners. Chinatown is a must see with plenty of stores so you could spend an entire day there. Be aware that it can be over crowded at times, but don't let that keep you away. You haven't seen San Francisco unless you have visited Chinatown.