I would say Lower Haight, Duboce or Cole Valley.. They all have their personality but most importantly it puts you a 10-15 minute Uber or Lyft ride from just about every neighborhood in the city.

Hi Lars,
Our city is small in area, and everywhere is easily accessible by public transit or uber/Lyft. With that in mind, I would suggest residential areas away from touristy districts. If you're staying in an airbnb/rental, I'd suggest neighborhoods like the Inner Richmond, Inner Sunset, Bernal Heights, and Cole Valley. These neighborhoods have their own great cafes/bars/restaurants, but you can still easily access busier or more popular spots.

You say you want to meet Locals ....
Okay ....I'd say stay in the Castro Area.
Lower Height ....even Hayes Valley.
These are the areas I'd recommend for
Meeting people.
The Mission can be an eye opening experience....close by is ....
Valencia St.
the hip happening street with a variety of shops ..restaurants ...and places to have s few drinks .....
Hopefully that helps you a bit .

SoMa (South of Market Street) is a bustling area but pretty pricey. Lot's of businesses in that area though and bars. Nob Hill is going to be older and more historic. Anywhere you go in the city is pricey. I have a friend in Potrero Hill and it's more neighborhood-like there and quieter. I'm personally a fan of North Beach which is way North and located by a ton of great restaurants and the piers. Hope that somewhat answers your question.

It really depends on what you want out of your experience. When you say based out of, it sounds work related? If it's for a vacation I would deifinetly recommend North Beach, The Marina or Upper Pacific Heights due to their fun and safe locations. They are more upscale so can be pricey. San Francisco is only 7 square miles and with all the different transportation options it's easy and fast to get around. If you are looking for some artsy and exciting spots, try The Mission for authentic Mexican food and uniqueness. Have fun!!

I like anywhere around the pan handle the best

Avoid staying in downtown or anywhere close to union square. It's quite busy and the homeless scene can be a little overwhelming.

I would suggest staying in Nob Hill, Russian Hill, North Beach or in the Marina. Those are all central places, and you can easily get to the sightseeing spots by bus or by taking the cable car (except for the Marina - the cable car doesn't run over there).

All those neighborhoods has its own soul. Lots of great restaurants and bars. If you wanna go out at night, the Marina and North beach are the best options. Russian Hill and Nob Hill have lots of great restaurants as well, but it's not as busy as NB and the Marina.

Hope you have a great time here :)

I agree with previous answer regarding what you can afford but there are some great addtional choices. The Marina is not a very diverse place, Russian Hill not much more. North Beach is a great location because of it's proximity to the Financial District, access to the bay, pretty good weather, etc. The Mission is more diverse with great restaurants, Delores Park is right there, and easy access to freeways to head out of town. Potrero Hill is pretty cool too with better weather (lots of microclimates in the City), easy access out of town, cheaper relatively speaking and lower key. There are many other choices depending on if you have a family too. Many families are out in the Richmond and Sunset districts but the weather, in my opinion, would discourage me personally from those areas...foggy much of them time but near the Golden Gate Park and more suburb-like. There are real estate sites that actually break down rents based on districts that you might find helpful. Hope this helps and good luck.

If you are OK with diversity, the Mission District is the best place because of the better access to roads and public transportation, and because this area enjoys more warmth and sunshine than most other parts of San Francisco. Exception: if you are an avid surfer, the outer Sunset District is close to Ocean Beach and surf shops.

As I am sure for most places, it really depends. If you could give me a little more information I could narrow my reply for you.

For travel or work?

For vacation or work?

Depends what you can afford. The marina is a nice place to live, top of the map, good running, biking, hiking nearby. Russian hill splits the difference between north beach and the marina, lots of options for food and local accommodations. The presidio is hard to get into but has a suburb feel while being in the city. Those are my pics. I'm sure you will hear a lot of other opinions.