I thought California. Has the best climate in the country?
https://en.wikipedia.org/wiki/Redwood_City,_California#Sloga...
Can confirm, don't need much AC or Heat year round.
As long as you locate to the area that most closely approximates your personal definition of 'best' you win.
If you think cool temperatures are more comfortable, then San Francisco is great.
Later this summer I’ll be hiking Mt. Whitney, and will swing through Death Valley on the way home. 15k altitude change in a few hours.