I don't live in SF anymore but when I was there I used to go to Yank Sing for work lunches. It's always packed and is definitely a westernized (but authentic) dim sum spot in that all the servers describe exactly what they are serving and most of the passed options are relatively mainstream. On one occassion I dined with a chinese friend who ordered off the menu and our server was more than happy to put in a special order.
This dim sum spot is definitely a little pricey so plan to spend a bit more than your typical dim sum place.
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