SO many things in San Francisco that are nicer than Fishermans' Wharf. Go there once, take your family photo in front of the sign, then leave. Well, actually, there's an interesting maritime museum in that area if you like such things. But otherwise, avoid it like the plague - it's a giant tourist trap of the worst order. Another fun thing to visit is the Sony Metreon (although I don't know if they still have all the interactive stuff they used to). They have an IMAX theater there, in addition to regular movies, and a nicer than average food court.
Not sure if Gasser's Camera is still around, but they're worth poking your head in to see. Their prices are usually pretty ridiculous, but they're an old-line camera store that's been around for maybe 60+ years. Ansel Adams used to shop there. Treat it as a museum/pilgrimage, not a shopping opportunity.
Food-wise - oh my god, where to start? San Francisco has some amazing food, and much of it reasonably priced. Cha Cha Cha is a fun Cuban restaurant - very noisy, but good food, prices are not insane. There's a couple of good Tapas restaurants within a block or two of each other in the Mission district, around 16th and Valencia. Ramblas is nice, and they have Flamenco shows sometimes.
There are some really great places to eat in the Ferry Building at the foot of Market street. If you're feeling the need to be reminded of home, and not put so much pressure on the budget, there are good cheap Chinese places near the night market in Chinatown, and a terrific bakery with dan ta, pineapple buns, and the fluffy white barbecue pork buns (I forget the name!) for 3 for $4 or 4 for $2 and so on. You can get several meals out of them for two or three people for $10-15.
Vivande Porta Via is a great little Italian place on Filmore. There's an interesting Pan-asian/Burmese place on Castro Street called Nirvana that's worth checking out. If that's not your speed, in that area there are a number of good little places along Market Street going downhill from Castro. Head out Geary Boulevard into the Richmond district for Russian food - Katia's Russian Tea Room and Cinderella Bakery & Cafe are next door to each other on Balboa.
For sights to see, I assume you'll have a rental car. Drive out Geary Boulevard all the way to the very end of it. It will start to drop downhill rather steeply, not far past the fire station. You'll see the Pacific (if it's not too foggy). On the right is a parking lot, just before the road takes a sharp downhill left-hand turn past the Cliff House (if you pass Cliff House, you've gone too far). Park in the parking lot, and you can walk down to the ruins of the Sutro Baths. There's a trail leading along the clifftops from that parking lot that takes you through some beautiful scenery, and brings you out after a mile or two to a viewpoint of the Golden Gate Bridge.
For another interesting view, drive across the Golden Gate Bridge and get off the first exit (I think it's marked Alexander Avenue). Go back under the highway and take Conzelman road up the hill which will give you an incredible view back over the Bridge toward the city. There are WW II vintage fortifications in the hilltops you can explore. Take a drive down Route 1 along the coast, all the way past Half Moon Bay to San Gregorio Beach. Get out and walk around for a bit, then turn left and take Route 84 up to La Honda, and keep going up over the mountains past Alice's Restaurant, then down the other side into Woodside and Palo Alto. You can get 280 back up to San Francisco to finish off the day. It's a gorgeous trek through coastal scenery, redwood forests, and mountains. Possible but not likely are sightings of deer, vultures and other birds of prey, and while almost impossible to spot given the time constraints, mountain lions are known to roam the forests.
Better buy anything you want before Las Vegas.
