Changing seasons instead of the monotony of hot and wet or hot and dry, beautiful architecture of old towns and villages instead of the uniform drabness in Thailand, not having to sit behind someone driving at 20mph in the outside lane, being able to sit outside with a beer in summer till 11pm while its still light and without getting bitten to death, vast choice of theatre, concerts, art galleries and museums if that's your thing.
One man's meat is another man's poison. There's no one size fits all answer, it's wherever you feel happiest.