Depends on what you want to see; the city is incredibly diverse. The denser, more urban areas are the ones developed before the car was the dominant form of transportation. Downtown, Macarthur park, koreatown, hollywood, etc are very dense. Some parts of the westside are too. The trains generally go through the denser areas. Much of it is gritty, but the architecture is cool, there's lots of fantastic food everywhere, and it's generally interesting. Go explore :)