One of SF's time tested spots, and it has passed the test for a damn good reason.  4 stars on Yelp is tough for a night club in SF since most of the people who like nightclubs don't like Yelping, and vice-versa, know what I mean?  It's got a reasonable cover ($10 usually), great drinks, a fun 25+ ish crowd, and a very cool underground dancefloor.  I play a tasteful and fun open format set here.