That wouldn't even be a choice for me. San Fran is cool but the stuff that's fun to do there is the same stuff thats fun to do in any city (wander around, go to some big parks, go to a club). Also there are alot of hobos, gays, and smelly hippies.
If you do go to San Fran though make sure to go to the International Spy Shop at Fisherman's Wharf. They have some dope shit there, I got a urban survival Chinese police dagger, its got bolt cutters and a sling shot and a spring loaded glass punch and a medical kit and sewing kit and a whetstone and guthook and a bunch of other crazy shit built into either the knife or the sheath.
Theres only one club in the city thats 18+ (as opposed to 21+), and I've never seen so many horny bitches in one place. So you should go there to. And Golden Gate Park is pretty sick.
But yeah I'd go to Bachelor hands down, every time.