I am a US citizen currently teaching English in South Korea. In August I will be going home and hope to take my Korean girlfriend with me. We plan to get married, but are not sure when yet. My question is what is the best plan of action?
A) Have her come on tourist visa, get married, apply for adjustment.
B) Have her come on student visa, get married, apply for adjustment.
C) Get married in Korea, then start Marriage visa process.
D) Get engaged, then start FiancŽ visa process.

Which method would be fastest? Easiest?
Which way would keep us together the most during the process (not in separate countries)?

Forget A or B... HUGE problems, there, neither are a path to a green card, and will result in huge frustrations, C) works if you are going to be in Korea until its issued, D) might be the best bet... again assuming at least she will be in Korea until its issued. Because that is a path to something permanent.

They are all fairly lengthy, and any lapse that would have her here illegally due to something expiring will only complicate the situation.

Trust me... been there, done that, got lots of bad advice from the INS themselves, nobody had INTERNET at home during that time either... and restrictions have gotten tighter since then as well.

I'd recommend Hiring an Immigrations lawyer... its going to cost you some money... but it will save you a lot of aggravation.