Well there are tons of things to see in Korea but not sure I would call anything great. I did enjoy my time there. I was stationed at Camp Casey/Camp Hovey(spell check on hovey, not sure I remember) during my time and I did have a blast. We spend a lot of time "down range" at the bars and enjoying the night life. The food was fantastic and we had a little mom and pop korean cafe right down the street from our unit so we ate lots of roman.
Not sure of your age or how much you party but be careful while in and around the bars, always go with a couple people and beware of the kettles they will bite you in the ass. Soju is pretty easy to hide in fruity drinks and while I was there a 32oz kettle was $2-4 bucks depending on where you went and they were about half and half soju and mix and would kick the **** out of you quick.
Other than that, have fun and be careful.
"We must reject the idea that every time a law's broken, society is guilty rather than the lawbreaker. It is time to restore the American perception that each individual is accountable for his/her actions." -Ronald Reagan-