You don’t say what nationality you are but I’m guessing you’re American. If I’m right and that is the case, the first thing you need to do is to find out about visas and work permits. I think it is difficult for Americans to get visas to live and work in Spain. I suggest that this is the first thing you look into because if you are not entitled to a visa, you won’t be able to work legally.
If you find that you can work in Spain (I might be wrong in my guesses), International House and The British Council have teaching centres in Spain. The British Council doesn’t only hire British teachers; I’ve seen various nationalities working there. Both of these organisations have good reputations for the quality of their teaching.
If you decide that Spain is not for you, I don’t really want to advise you on your choice of country. This is a major decision and one that only you can make. Some things to consider when making your decision are:
the type of culture you like;
what languages you speak or you already have an affinity with;
the climate that suits you;
what job prospects there are;
what the salaries are like;
how easy it is to travel between your home and your chosen country.
If you have any further questions, I will be happy to answer them.