Slanted Door is a fine restaurant. Upscale Vietnamese. Lots of shops in the Ferry building where it is located.
If you have time, walk a few blocks south along the Embarcadero for great views of the SF Bay Bridge.
You might also want to stroll along Market Street, one of the main thorough fares in SF, although in this area there are mostly financial buildings. You can catch a return BART to SFO at several places along Market St. not far from Embarcadero.