California's Next Five Cities (In Order Of Importance)...

[TheFlats]

Usually the Bay is broken up into SF, Peninsula, South Bay, East Bay, etc. There's a reason the Peninsula is specifically separated from the South Bay, it does function as it's own sub-region.

[RussellMoon]

I agree that the San Francisco Bay Area is not really one region. Locals generally divide up the Bay Area as follows:
1) San Francisco (the city itself)
2) South Bay (Mountain View to San Jose/Los Gatos)
3) Peninsula (Palo Alto to San Mateo - more or less)
4) Marin County (north of Golden Gate Bridge up through Santa Rosa more or less)
5) East Bay (Milpitas up to Berkeley/Oakland area)
6) Wine Country (Napa, Sonoma and surrounding wine growing towns) - not sure most people consider the Wine Country to be part of the SF Bay Area but some people might since it's part of the greater tourist region of the Bay Area
7) Santa Cruz County (Scotts Valley, Santa Cruz, Boulder Creek, and other bedroom community towns south or west of Los Gatos) - again not part of the greater SF Bay Area but many people commute over "The Hill" to work in Silicon Valley

Silicon Valley sometimes also includes Palo Alto but Palo Alto is generally considered to be part of the Peninsula rather than the South Bay. Milpitas might also be grouped into South Bay as it is both south and east.

There are also some towns south of San Jose like Morgan Hill, Gilroy, etc. I guess they might be considered part of the South Bay but generally not considered part of Silicon Valley.

[KazChasey]

1) Greater Los Angeles (Everything from Ventura to Camp Pendleton)
2) Bay Area (SF, Oakland, SJ, etc.)
3) Greater San Diego
4) Sacramento Area
5) Central Valley (Fresno & neighboring cities)