KLIFF (Korean Language Institute for Foreigners). The classes there are excellent and tonnes of fun!
Often before class or after I've been dropping by one of my old favorite haunts : Chabatgol Teahouse. It is easy to get to:
Just go up the street as if you are walking up to Pusan National University's main gate. Up ahead you'll see the NC shopping mall on the right. Stay on the left side of the street and keep going up the street.