The answer the best reasons to retire&

The answer the best reasons to retire overseas has multiple answers and the right one depends on your own lifestyle, family situation, health, monies and more.
We decided to move and work towards retirement in Nicaragua. We checked out Costa Rica, Panama, Belize, Colombia and Chile. We skipped Mexico due to many retirees and also high crime rate. Our main reasons where based on economics, ease of travel between US for our kids to Nicaragua and us back to the US to visit kids and handle our business. We also looked at health, local business environment and government incentives for retirees.  
We also have a tax advantage by working in Nicaragua and keeping a good amount of this income tax free from our US income taxes. 
Here is one additional item to consider: to succeed as a retiree overseas will require an open mind, a willingness to experience and embrace new ideas, smells, sights. 

Best Places In The World To Retire