Ask HN: What should I do in San Fransisco?

Hello all,

My fiancee and I will be visiting San Fransisco in a few weeks. Are there some awesome touristy-to-not-so-touristy activities/sights/hits/misses that we should absolutely not miss?

My lady and I are both into science and technology (I'm an epidemiologist, she's a MD), but also sports, wine, good food, all the good stuff.

We're also always up for meeting new people. Although we're not entrepreneurs or hackers (yet), we're reasonably interesting!

I'd appreciate any suggestions!