If you are a JET and want to teach in other countries, especially in Europe, a professional 120 hour TEFL TESOL certification is highly desired or required (regardless of teaching experience).
International TEFL Academy trains over 1,200 new teachers a year with 4 week fulltime courses in 25 locations worldwide or 11 week part time an online TEFL course. Students find work all around the world.
Here is a chart of the top 50 countries people teach English: http://www.internationalteflacademy.com/country-chart-world-index-english-teaching-jobs/
This article is for the Top 10 Job Markets for Teaching English Abroad
International TEFL Academy is based out of Chicago, USA with British Accreditations. Lifetime job guidance for all graduates.