People ask me where I often like to go eat and I have to say that I go to Edward Kwon's Eddy's Cafe quite frequently. Service is always friendly, the food is not too expensive, and the quality is top notch. Here is a Chicken Frittatta and a Mushroom Velote soup I had at my last visit.

Eddy's Cafe
Shinsaegae Department Store in the basement
Express Bus Terminal (Subway Line 3).