Golden Gate Park is one of the nicest parks i have ever been to. Steinhart Aquarium(im not sure if it has moved or something?) is the 2nd best aquarium i have ever been to, with Monterey Bay Aquarium Winning out here.
The Dragon Well is in the top 3 Chinese Resturants I have ever been to.
I've been to the San Francisco Opera House twice and it is the most beautiful building I have been to in the United States.
This one should be pretty obvious, but ATT/SBC/PacBell park for Giants Games. This is my 2nd favorite baseball stadium after Wrigley field. The view is just spectacular.
The whole area by Fishermans wharf is pretty sweet. I am a seafood lover and the clam chowder/all dishes around here are just fantastic. As is the sourdough pizza. damn, now i want some sourdough pizza. My uncle's favorite restaurant is Scoma's, right by Fisherman's Wharf, but i prefer Pompei's Grotto.
I had a few friends who went to SF State, I def got drunk and partied and met lots of cute girls there on a few occasions, fun part of town. Also, that long beach near there rules. Isnt it called Ocean Beach or something?
I live about an hour from SF, so this is the best i could do. Like Evan said, i couldnt part with the delicious Mexican food that Taqueria Santa Cruz makes me almost daily. Seriously ridiculously good.