Coffee shops abound on Garosugil. There are plenty of restaurants too, but the first thing I noticed when I turned down the street coming from Sinsa station were the myriad cafes. If I were to return once a week for the remainder of my time in Seoul (how ever long that may be), I'm not sure I could visit all of them.
There are also many interesting-looking restaurants sprinkled throughout the neighborhood. When I'm more flush with cash, I'll have to come back.