I was the Executive Officer of Military Sealift Command Office Korea in Busan from July 09 to Jul 10. It was a non-flying tour for me but a great tour. I remember back in 1999, my first port visit in the Navy was Busan and I saw one place, Texas Street. The USS Constellation pulled into Pier 8, where my office was the MSCO command is. So when I got orders, I didn't have fond memories. Once you live in a place though, you learn the ins and outs. Busan is a great place.
However, you are in Osan, good shopping but not much to do. Great base though. If you get a chance, during the summer, go down to Hyundai Beach, go to Fuzzy Navel and all the bars in that area. Lots of ex-Pats, things to do. If you like Asian food, you are set and if like Asian women, even better! Seoul is a great place too but I didn't spend much time there. Remember, there are something like 10,000+ Ex pat teachers in Korea, most female. Good times for all