LA's culture is more on the side of consumerism (Hollywood & Disney),
instant satisfaction (McDonalds', Jack-in-the-box, Carl's Jr., In-N-Out, etc),
and sandy beaches (bikinis).
San Francisco's culture is more unique:
Castro District (LBGT),
Height Ashbury (Summer of Love/Hippie),
Berkeley (Free Speech Movement)
Allen Ginsburg (Beat Generation)
Oakland (Black Panther)
North Bay (Wine Country)
South Bay (Tech)