Where is the nicest (low crime rate, less traffic, lower population) area in southern California to move to?

Just wondering from those who have lived there or are living there where the nicest overall places to move to would be. Preferably somewhere along the ocean, or a smaller population. I am from small town Nebraska, don't like driving in high congested traffic if I can avoid it. I would like to move to this area at some point in my life and would just like some helpful hints!!!