I love stopping by Galleria whenever I'm in the area.
While some of the groceries are a little more expensive than your average grocery store, I don't come here for groceries. Galleria offers so many options when it comes to prepared foods. From fried chicken, to bulgogi, to gamjatang, to sushi, to buns, you can try something different every time you stop by. There's also a food court that offers a wide variety of Korean food if nothing in the actual supermarket tickles your fancy.
Everything that I've tried here is really good. The red bean stuffed fish cakes are really good, so make sure you try those when you're there. For $1.25 each, it can't be beat.
I also love how the employees (cashiers) are dressed in traditional Korean clothing during the day.