Noryangjin Fish Market
One of the largest fish markets in all of Korea, Noryangjin offers up nearly every edible item found under the sea. The famous fish auctions take place around 3AM, making it an unattainable site for most, but the market itself is worth a visit to see.
Time your market to the trip around meal time, find some delicious and cheap offerings, and make your way upstairs to the restaurants who will cook up your fresh seafood for you for a nominal cost. While there, you can also order sides or booze to your meal.