Has to be Michael Holding. Coolest man ever. And somehow he even pulls off being called Mikey. When there is a clear LBW his line of "The man who comes to fix the pipes couldn't be more plumber" is a personal favourite of mine.
Not sure about the coolest looking but to buzz Allan Lamb and Robin Smith in a Tiger Moth after being dismissed himself is pretty damn cool in my book. Gower gets my vote.