Keokbokki, which is a broiled dish of sliced rice cake or sticks of rice cake with eggs, oden and seasoning, is a typical street food of Korea. But you will find that it tastes rather polar place to place. Shindangdong is most famous for it but I recommend H.O.T Teokbokki in Haehwa.
Get off at Haehwa station and out through exit #4 onto the road to Sungkyunkwan university. On the left, about half way up you will find a small cozy bunsikjib plastered with posters of legendary H.O.T., singers of 1990s.
One cannot forget the spicy yet tempting flavor of Teokbokki there.