Cho Sun Ok (a little south of K-town on Lincoln) is a cool authentic experience. There is usually a line out the door and Korean families like to frequent it. It offers a little different experience that the standard - the thing to get is chadul gui - its what all the Koreans will be eating. They do a nice fried rice with your leftover panchan at the end of the meal. It's nice for something a little different, but still super-authentic.
I like Solga, too, for Kalbi or soups/stews. The panchan are pretty good there, too.