Gasser's is definitely a waste of time these days.
Photographers Supply is good for film, but not much else. Vic(The Dick) is a bit gruff, but they do carry a fair amount of film.
Rayko has film, and darkrooms, but the camera selection is pretty sparse.
Glass Key is a great store. Lots of film, darkroom supplies, and the owner is a nice guy.
I think Action Camera has closed, but maybe not. They were always kinda rude, anyway.
Looking Glass is worth the trip over the Bay.
If you're in Marin County, Seawood is always good for a visit. They claim to have the largest selection of used gear in Northern California, but I kinda doubt it. Their M case is sometimes plentiful, sometimes empty.
Camera West is well worth the drive to Walnut Creek if you have real money to spend.
Finally, if Camera Heaven(in the Tenderloin) is still around it is worth having a look. It's a real mess of a store, but there is sometimes a Nikon S2, or maybe an M or two on the shelf.
Good luck.