Mark Sanchez and company have taken the Jets to the AFC Championship game two seasons running, that is a great accomplishment considering he has been in the league two seasons. He has greatly improved in his second year and I see him only getting stronger, faster and more intelligent in his decision making.
Of the four listed, Matthew Stafford has the ability and intelligence that a great QB needs. He remains prone to injury, dumb luck or inexperience, I am not sure. Other QB's play consistently with injuries. If he remains healthy, Matt will put up some numbers and guide his team to winning.
Tavarius Jackson has not had enough playing time to evaluate effectively. I believe he has the talent, unfortunately he has not been able to showcase it.
Vince Young has had a few years in the NFL, his attitude overshadows his on the field ability.
I really have not seen that jump in his play that is quite visible with Sanchez or other QB's that have matured with each season.
I would take Sanchez first, he has improved, has a good team with good coaches surrounding him.
Next, I would take Stafford, he has the talent but needs to remain healthy. Jackson, I would love to see what he is trulycapable of, and Young would be last. His ability is overshadowed by other issues, deep down it has to be him. All those teams cannot be incorrect in assessment.