Union Square Area

Come to Union Square if you love to shop and want to be near the start of the main cable car line.  It's also close to SF MOMA and within walking distance of the newly renovated (and well-worth seeing) Ferry Building at the foot of Market Street.  Just be aware that a lot of street people hang out around here and that parts of this area are not always pleasant.  On the other hand, you can't beat the price and it's central to just about everything.

Fisherman's Wharf

Fisherman's Wharf is everything you've ever heard about and more.  It's not the working fishing wharf it used to be 30 years ago, but still has its roots firmly in the old fishing tradition.  You'll see it in the great restaurants, and in the gorgeous view into the Bay, with the Golden Gate Bridge to the left and Alcatraz straight ahead.

There's a ton of stuff to do and see right here and it's at the end of the best cable car ride in town, so you don't need a car.

Cow Hollow / Presidio

This is a great location if you want to be at the north end of San Francisco so you can see the Golden Gate Bridge, go to Sausalito, Marin County and the Wine Country.  It's also very close to the Presido where you can drive along the top of the Bay where it meets the Ocean and come around by The Palace of the Legion of Honor, Cliff House and the Beach and the beach end of the Golden Gate Park.

Just be aware that Lombard Street is a main drag into and out of the City and can get extremely congested during rush hour.  On the other hand, there are plenty of side streets so you can by-pass the worst of it and get where you're going.