My criterion is which guy would I want to start one game I had to win. Also I am only picking from those I actually saw play significantly (after 1980)
1. Dan Marino. Quick release, great arm, an absolute killer with the ball in his hands. Never had a great running game our defense to help him.
2. Joe Montana. Joe Cool. Great accuracy and always played great in the big games.
3. John Elway. The prototype, great arm, great mobility, and an excellent leader.
4. Troy Aikman. Excellent arm and tremendous accuracy and also played his best games when it mattered the most.
5. Tom Brady. People seem a little down on him after the super bowl choke, but he is a tremendous player. Good arm and accuracy and sees the field as well as any QB ever IMO. Also played his best games on the big stage.