Haight-Ashbury, North Beach, Tenderloin, Chinatown, Russian Hill, Marina, Embarcadero, Castro, South of Market, Telegraph Hill, Pacific Heights, off the top of my head. I lived across the bay so I accept that I know more than average.
My sense is that a few are more well-known than the neighborhoods of most cities, but in the grand scheme, no, which is why its easily the least-guessed answer. San Francisco has more cultural influence than any US city other than NYC or LA, so that gives it just enough notoriety to make this a reasonable question.
https://www.jetpunk.com/explain-points