Or 일공육 라면, is a 24/24 ramyun restaurant in Hongdae. Price range is 5000-6000 won and they have three type of ramyun, sausage & cheese, seafood, and I don't remember the last one. XD They give you a free slice of raw fish as entrée.
You can drink unlimited pepsi or cider, eat free eggs, and even bread and peanut butter ! Oh, they have free mini bowls of rice too.
The ramyun here is really good, the restaurant is often full and you have to wait, even when we went at 4am in the middle of the night on a weekday, we weren't the only customers! ^^
How to get there? Hongdae exit 9, go to the main street to Hongik University and go past the KB bank! It's just in front of the "Frisbee" (Apple retailer) store.