Los Angeles Koreatown Eatery, Sul Lung Tang
This is a soup that takes hours to cook, and this restaurant does it right. It's on 8th Street and Serrano (on the Southeast corner). This is as authentic as it gets as the menu is mostly in Korean. They cook the broth in 3 huge vats. If you have a hangover, or feeling slightly less energized, most Korean eat this soup. They also cook their rice with chestnuts and dates in a stone pot.