Tum Sae Ramyeon
In Myeongdong there is a famous Ramyeon (or ramen if you prefer) house. It is down the main drag from the big movie theater. And don't worry, if you can't find it, just say Tum Sae Ramyeon- a curious bystander will point the way.
The Ramyeong is spicy. I mean really, really, REALLY spicy-but don't let that deter you. The cooked and drained noodles are put in a pool of spicy gochujang laced broth (but I wouldn't encourage you to eat the broth unless you have an adamantine stomach). The flavor is rich, powerful and the aftermath is the best food-endorphin induced high. It is literally fire in a bowl. I want to go back and feel the burn.
The staff is super friendly, mom-like, and there are thousands of notes all over the walls. This Ramyeon house has been featured in the Times magazine, and KBS. Check it out.