I really hate people signing off emails or messages "With kind regards". It's not up to me to describe myself as being kind, it's up to the recipient of my supposed kindness to decide if I am getting it right.
I much prefer "With best regards" to someone I don't know, or "Best" to people I do know. I am better placed than anyone to judge if I am sending them my best. Sure, "best" has something of the value of "most favoured nation" about it, but that's still not bad.