Who are the greatest warrior and fighter in Mahabharatha?

There was always this question who was greatest? Bhishma, Drona, Karna, Ashwadhama, Arjuna or Bhima...
There are many instances in Kurukshetra and otherwise which proves and disproves many things. I looked at what KMG and few other versions which I have and wrote this.
My take on that question is this piece..