Depending on your career path and the size of your bank account there are two schools in SF - The California Culinary Academy and Tante Marie.
CCA is a lot more expensive at (are you sitting down for this?) about $50,000 for a year at school and a 3 month externship.
I don't know what Tante Marie is charging these days but it is a lot less than CCA - probably half or more. Theirs is a shorter program too at 6 months I think.
If you want to venture out of the City to the Silicon Valley, a new school called Pacific Cooking School (PCS) opened about 2 years ago. I don't know a lot about it but what I have heard is good.
CCA takes a lot of flack about being owned for CEC in Chicago and being all about the $$$ and you will hear a lot of debate about whether the education you get is worth the $50K (plus living costs if you are from out of town.) The answer in my opinion is that is entirely up to you. If you are committed to your chosen path the rigorous courses will teach you what you need to know to get started - in spite of any extraneous crap that may be going on around you.
Tante Marie's is a much smaller - almost store front - school but the staff is no less dedicated and the students tend to be more focused.