Korea Taiwan and Japan
Ok, for what its worth, here's my experience. I am currently finsihing up a year contract in Japan. I will be here another year at least. I taught in Taiwan for a year before this, and Korea for a year before that, and in between korea and taiwan, I got a teaching certificate in Thailand.
Korea: I lived in a small BFE town that was boring as hell. I went to busan most weekends. I had korean GF in the states for a couple years, but my opinion of them is they are very whiney and materialistic. the only girls I saw with whiteys in my small town were B5 at best. The pay was the best, the teaching was the easiest (no time required for lesson planning, just show up and play english games with the kids). If you choose Korea, shoot for Seoul. Lots of sketchy schools that don't pay, lie to you, etc. BUT if you are in the states, Korea is by far the easiest to get into, and they pay for pretty much everything. You only need to show up with food money for a month. People you meet on the street aren't that friendly.
Taiwan: Friendly people, iffy food, lower salaries, no paid apartments. Better girls IMO. Better attitude, but not as good looking. All you will teach is kids. Hot and sticky from spring through fall. Lots of fun stuff to do on the weekends (bars, clubs etc) I lived in Taichung, which is a fairly sized city.
Japan: Friendly people, good food, salary between taiwan and korea, but you gotta pay for your flat. By far the best girls. Dress classy when they go out, very polite and feminine. Can be kind of spoiled though, as almost all kids are pretty spoiled by their parents. its not uncommon for kids to live at home into their 30's, and sometiems not working and just living off of dads paycheck. They call these NEETs (No Education, Employment or Training). If you have any kind of social skills you'll have no problem with the ladies. Problem is , now its hard to get a job in a decent sized down. So you might have to setttle for a place out in the boonies, where NOBODY speaks english. For example, I sent my resume into a job in Osaka (2nd or 3rd largest cities) and I was one among aobut 150 resumes. And lots of places ask for experience.
I was in Thailand for six weeks, and loved it. Very friendly people and nice girls, but the pay is crap, otherwise I would have stayed there.
PM me if you want any more information, but yea, deciding to come to asia to teach english has been one of the best decisions of my life.
i was an engineer for 10 years and that was boring as phuck.