Swan Oyster Depot was at the top of our SF list. If memory serves me right we checked into our hotel and drove here in our rental car immediately after dropping our bags off. There was a line but it was nice out, we got Anchor Steams and it was okay. You could feel the history of the place oozing from every corner. Part of what made the wait pass quickly was that the energy of the staff was bouncing off the walls, except that as you come to the front of the line you are actually standing in the shop and watching people eat at a point in time when you are particularly hungry. The meal was a highlight. (We ate much more than what is pictured below).
Design note: that brass fish door pull slays me. The most perfect touch.