Burger joints that started in SoCal:
Habit (1969, 147 locations)
In n Out (1948, 313 locations)
Carl's Jr. (1941, 1385 locations)
McDonalds (1940, 36,615 locations)
Listed in order of selection, by truth_seeker and wife, SoCal natives and residents.
A couple of years ago, McD's revamped their menu and pricing, and I never go anymore.