Best states to retire is subjective. Lots of people says Hawaii and western continental states, but if you have family back home and something happens that you need to be there in a relatively short amount of time, it's not going to happen that far away. Even if you just want to be at your grandkids middle school graduation or whatever, it's going to cost a bunch and going to take a good while to get there. Heaven forbid you have a loved one on their deathbed that you would like to see before they pass or just be there for someone else to lean on.
I've been researching this for years and more goes into where you want to live than many think.