All countries have their pros and cons. What sort of culture do you like? Or even what type of food do you like?
Korean food is hot and spicy. Japanese food is gentler to the pallate. Chinese food is oily but very delicious.
And weather? Hot and humid summers? Milder summers? There really is a lot of questions to ask oneself before deciding which country to teach in.
What about language? Will you learn the language? Do you want to do business with the language in the future?
Friends, money, savings etc... all need to be considered.
Sorry, I suppose you were looking for a 1 worded answer. But this is almost impossible I think.
I'd make a great politician right? Never answer the questions. Hahahaha