Druid Hills. One of the wealthiest cities in Georgia is Druid Hills, which is situated in DeKalb County. ... Decatur. With 8,906 homes, Decatur, a city in Georgia's DeKalb County, is among the wealthiest regions of the state. ... Milton. ... Berkeley Lake. ... Dutch Island. ... Skidaway Island. ... Alpharetta. ... Brookhaven.