It’s cheap
It’s not overly touristy
It’s close to lots of day trips, like trekking or the Burmese border
There is so much culture
It’s easy to stay in Thailand long term, by renewing your visa in neighboring countries
The food is amazing
The people have been wonderful and the expats and locals live together well — there is some division, but you’ll also see Farang and Thai families eating at the same places
There is a lot of volunteer opportunities
It has an airport
It’s close to a major hub (Bangkok) for cheap international flights
It’s laid back
There’s nightlife if you want it
There’s every imaginable self-improvement class you can imagine: from yoga to cooking classes to Thai massage
It’s family friendly
It’s warm (no winter here, but there is a rainy season)
Medical care is ultra affordable
In short, the quality of life is extremely high and the cost is low