In the interest of practicality, I've broken this guide into two parts. The first, places to go when you're on a healthy expense account, and/or with clients. And the second, where to go when it's your buck, or after your clients have gone to bed.
Plumpjack's (415-563-4755) has a wine shop next to it. Great food, as long as you're not a bunch of vegetarians.
Mecca (415-621-7000) Good bar with a N.Y. feel. Good food too.
La Folie (415-776-5577) Yeah, it's French. The food's rich and expensive. Lots of courses.
Boulevard (415-543-6084) Cool art nouveau interior. Interesting menu. Pretty expensive but worth it.
SuppenkÜCHE (415-252-9289) German, family-style restaurant. Good bar, obviously lots of good beers. The place keeps pretty busy, so it's better to go in off hours.
Slanted Door (415-861-8032) Good, cheap Thai food. Pretty self-explanatory.
El Toro (415-431-3351) (on 17th and Valencia). Cheap, good taqueria.
Mr. Bing's (415-362-1545) Tiny dive bar on Columbus. Usually safe, but not a bad idea to bring a weapon.
Chameleon (415-821-1891) Seedy club with live punk music. Lots of different beers on tap.
Enjoy, and remember, cabs are a bitch to find here, so call early.