Kerri Salls summed it up nicely. It is my sense of purpose and passion that give me the persistence. Never, never, never give up - a standard I live by.
The other thing, I think helps professionally is to work harder on becoming the person you know you were meant to be and not the person you are expected to be.
Determination. Entrepreneurship is 10% idea and 90% execution. I've found that those who devote themselves fully and consistently to their new business idea to move it forward are already ahead of most other entrepreneurs and more likely to eventually succeed.
I am not sure I can rank them but something I have always admired (and envied) in an entrepreneur is good decision making skills. ;)
Passion definitely helps.