You know who'd win? Bacon. Bacon would stop every one of those bad-asses in their tracks. (It was obviously left out of the poll on purpose.)
Christian Wolff vs John Wick would be interesting. They both like to shoot people in the head. For those of you who don't know who Christian Wolff is. Ben (Douchebag) Affleck's character in The Accountant.
I'll go with Frank Martin, who you seem to have left out of the competition. And how could you skip Bryan Mills?
Seriously, Pam Grier...Coffy. All those others would be to busy looking at those puppies to notice the gun in their face.