I thoroughly enjoyed my last visit to San Francisco. I have family who lives in the City pero the number of times I'd go there would always be with other relatives and ofcourse they had their own IT, so in my last visit I did my own walking tour and then some. If you're commuting look for the Rover app it gives you bus frequencies and times to get to places, and your iphones GPS will come really handy to for any unplanned walked lalo if you are in no rush.
The Cartoon Art Museum close to Union Square it's where the other museums are at and it's a small little place that you can easily miss so just be on the look out or have that gps handy. They were celebrating Superman's 75th anniversary I think they have it on till September. They celebrate different themes, and most displays and artwork come from private collections. It's a cozy little museum the fee is less than $10 and it has a small bookstore beside the entrance lotsa nice things to see, I also got to read one book while killing time and before I got hungry.
Yank Sing, just because I had to try their Shanghai Dumplings, you'll read a lot about it being pricey and that there are other better dimsum places true din, but I liked the ambiance or just dining with the rest. take home some chili sauce they sell in bottles nice pasalubongs.
La Mar,http://www.lamarcebicheria.com/san-francisco/ (parang di complete the menu listed) a peruvian restaurant, at the Embarcadero is yummy order their chicharon sandwich this one will make you want to come back. Skip the empanadas, not that its not good but coz there are other places for the empanadas din. Price isn't as bad and surprisingly affordable even if you just share dami the servings and the ceviche will tickle you pink, I bet everything on their menu is good and sulit.
Far down the Pier there's a restaurant called Cioppino said to have the best Cioppino, per Emeril (as posted on their window) but I went there for Clam Chowder. It was good too don't order the bread bowl they serve bread anyway so that'll save you a couple of bucks din, but i think the Cioppino is a must, it is after all an original SF dish.
Then there are the museums around and the ships that are docked you can go in an out for $5 it gives you free entry to what the Maritime Museum covers
http://www.maritime.org/hours.htm Hyde St. If you have kids they have a cool tour specially made for them oh i think it's this one
http://www.maritime.org/edu/index.htm this is a fun hands on experience and nice for the kiddies if you have time to spare.
Another funky museum is the Miror Maze at the Pier fun at first and dizzying when they strobe the lights. Guapo pati yung guy manning the place.
Theres another ship docked close by and where the Museom of Old Carnival Games is at. I think those are nice to visit for first timers or for the fun and novelty of it.
You can probably skip the Aquarium nice din but siguro the one in Monterey Bay is worthier to visit.
If you have kids go visit the kids store Lola at Ghirardelli square I always end up buying something from there. Dun kasi ako nakakita ng scaled down instruments, actual instruments sized for the kids to learn on.
Other nice spots if you have someone to taking you or if you drive around is Humphrey Slocombe
http://www.humphryslocombe.com an l.a. version of this is Sweet Rose at the Brentwood Mart - pero original si Humphrey so yeah this is a good place for an ice cream break they have a wacky twist of flavors and everyday is different.
Souley Vegan
http://souleyvegan.com if you want Soulfood the healthy way, servings are a lot, the drinks are good, the dishes are so flavourful. Scary lang ata ang part of the town na ito.
Sam's chowder house in Half Moon Bay, scenic drive yummy chowder I think I liked theirs the best it's carefully seasoned and far different from the chowders I tasted around the square and to wherever else I had clam chowder. The lobster roll is what they're known for and a must, you won't go wrong din naman with the other dishes. But if you want to enjoy a whole lump of lobster that's the place.
There are a lot of other nice places pa if you want to venture around so far these were the ones that I enjoyed going to.