I completely agree with @KeithCollantine. That is the reason why I usually avoid ‘who’s-the-worst-driver-ever’ type of discussions.
If anyone wants to get to know more about Phil Hill, I suggest you to buy this book that I am currently reading:
http://www.f1fanatic.co.uk/2012/01/11/limit-life-death-formula-1s-dangerous-era/
