Welcome to Chowhound, with an area greater than 4,000 square miles and a population greater than 9,000,000 for Los Angeles County only (the Chowhound L.A. board actually encompasses Los Angele, Orange and Ventura counties and part of San Bernardino county) your query is too open ended. Please supply additional criteria, such as price point, cuisine (e.g. Hong Kong style seafood, American seafood, American steakhouse, Japanese steakhouse, Mexican seafood, American BBQ, Korean BBQ, etc.) and neighborhood or how far you will be willing to drive from where you will be staying.
In terms of the San Francisco Bay area, we have a separate forum just for discussion of that area.
You may wish to spend some time just scanning through the large body of previous discussions on both the L.A. and S.F. boards in order to get an idea of what is available.