I agree with Vavoon and Naptown... although Favre is a great QB, I'll never say the greatest. He just has always had a knack for making a big mistake in crucial times. That INT against Philly in the playoffs last year was the most recent. All one needs to do is look back to Super Bowl 32. Greg Robinson called a great game and Denver totally forced Favre into some bad plays but Favre took a lot of chances and his team got burned because of it. He is a live by the gun/die by the gun type of QB. I doubt Favre wins another championship before he retires... that is just my feelings. He has lost the edge that he had early in his career and his skills have eroded to a point. Injuries are also becoming a factor. I'll be the first to admit being wrong if I am but I doubt Favre walks away with more then one ring.
As for Manning, Naptown I totally agree. If Manning had half a defense in Indy he would be bringing some rings to Indianapolis... the problem is with all the money tied up in him and probably EJ or Harrison this next year its going to be hard to ever build a top notch defense to help Manning get those rings. If there was a year to do it, it would be this season if they are going to win... I can see Indy winning this year but after this season its going to be dicey with all the potential free agents they have.
As for McNair, when I think of him, I just think of a very good QB that survives on grit. I don't really think of a great QB or even an MVP. He's fun to watch and he is definately tough but not in the class of a Manning or even a Tom Brady.