i recently went for lunch at chez nous on fillmore street and i was pleasantly surprised by their tapas. the tip off should have been the throngs of people waiting at lunch on a thursday at 2pm in a neighborhood district. the tapas were done quite well and better than some mediocre tapas places I encountered in barcelona.
in particular, i would recommend the gigantes (white beans sauteed with tomatoes, basil); grilled asparagus and croque paysan.
so the next time you are out near fillmore street, I would definitely recommend giving that restaurant a try but be prepared to wait, to yell above the din and to be crammed into a rather small table.