Simply put, I love food. If you're the same, the Ferry Building is a must visit on your trip to San Francisco. There is a Sur La Table, wonderful restaurants, a caviar bar... the list really just goes on and on. If you're in to cheese, you can't bypass the Cowgirl Creamery (see photo.)
If you can dream it, it is likely in here somewhere. There is also a farmers market which may be of interest.