Are you concerned you're getting ripped off by restaurants that serve low quality food?
Do you feel that you've just stayed five days in a city and know nothing more about it than when you arrived?
If you answered "yes" to these questions you are suffering from conventionitis.
Don't let that happen to you in San Francisco. Here are some of my favorite restaurants. The fancier ones require reservations, but during the week they shouldn't be too hard to come by. If you don't see a genre here, that certainly doesn't mean San Francisco lacks it. It just means I haven't eaten there.
http://www.ofcourseimright.com/~lear/sfrestaurant.html
Eliot ps: no, I'm not keeping a list to be updated.