To expand on Korea a bit, there are two types of jobs, hagwons and public schools.
If some guys could post a more detailed review about China, Japan, and Taipei in a similar vein to what this post does, we can have more clarity of information.
Public schools are government run, and as such you get more paid holidays, roughly 20 days a year + 18 national holidays + upto 15 sick days. You will always be paid on time. You get paid $1250 upon entry to pay for your flight costs (so if you get a cheap flight for $800 you pocket the difference), and the same upon exit. You also get $275 entry allowance. Starting pay is usually $1900 a month, but after 2-3 years and depending upon your education, you can earn up to $2700 for the same job. 22 classes per week. At the end of the year you will get a year bonus, equivalent to one month full salary. Your contract will be honoured.
hagwons are private language schools. In reality they are businesses. They are always treading a fine line between daycare and education, and the bottom line is profit. As such you will be usually paid more, starting at around $2050 a month, raising with experience to up to $3000. However, I think the downsides are worse. For example you get less than 10 days holiday advertised in your contract - the boss will pressure you not to take your holidays and act as if you're asking for the earth - despite the fact its written in pain English in your own contract! Sick days 3. Slightly longer working hours 25-30 classes per week. Same other benefits as public school, free apartment, free flights, bonus equiv to one month at the end of the year. Hagwons can be good, but be picky! Re-write your contract you get offered to clarify the English (it's usually poorly worded) and modify things you want to have changed.
http://www.youtube.com/watch?v=t8XAch40z8E is a good video on the hagwon vs public school issues.
The best jobs by far in Korea however, are Uni gigs. Short workings 12-18 a week, usually only 4 days a week, loooong paid holidays or 10+ weeks. Free apartment. Slightly less pay, $1700 a month, but way better lifestyle! Usually you need 3-4 years experience, some form of teaching cert like CELTA or - probably more valuable - a hook up at the uni.