I went to the recently opened Hog & Rocks this week for the first time. We had six odd varieties of oyster, all super fresh and nicely explained both in menu and by the staff. Saw, unsurprisingly, a whole lot of oysters being consumed around the restaurant, so I would imagine there's good turnover. On top of the oysters we had a nice heirloom tomato salad and excellent fish & chips. Great service and nice booze/wine selection as well. A bit crowded at 9PM but lots of open seats an hour later.
Hog and Rocks
3431 19th St, San Francisco, CA 94110
I perfer Swan Oyster Depot, but would also endorse Hog Island.
Have not tried Waterbar.
I don't like Zuni, except for oysters and cocktails, so I'd endorse that as well.
Bar Crudo is wonderful, but the oysters were not the highlight.
Anchor Oyster Bar is also nice.
Overall, specifically for oysters, I give it to Swan, then Hog Island, then Zuni, then Anchor, then Bar Crudo. (But if you want things other than oysters, Bar Crudo goes to the top of the list).
1658 Market Street, San Francisco, CA 94102
655 Divisadero Street, San Francisco, CA 94117
Swan Oyster Depot
1517 Polk St, San Francisco, CA 94109
Anchor Oyster Bar
579 Castro St, San Francisco, CA 94114