When I heard Manning say he was the best, I didn't think it was cocky at all. He was asked a question. He didn't just come out and say it.
The debate about Manning and McNair is just like the Elway and Marino debates. One is a pocket passer, the other is a playmaker. Manning has a much better supporting cast on O than McNair, just like Marino had over Elway. Put Manning on the Titans and he struggles big time. The same can be said for McNabb. He has nothing around him, but he makes plays on his own that help the team win. Manning would struggle on the Eagles. I think both McNair and McNabb would do pretty good with Harrison and Edge.
As for Brady, I've said it a number of times, he's pretty good, but he's very overrated. He gets more credit than he deserves. He's the only star on that team, but he's a star because the media has made him that. The Pats D goes out and wins the game, and Brady gets most of the credit. In 5 of the 6 playoff wins for the Pats, Brady was a total non-factor. Only this past Super Bowl Brady had a big game. I think at least 7 or 8 QBs could have won the Super Bowl with the Pats. Great D and a very low risk, dink and dunk offense. Brady is good, but I wouldn't even think of putting him in the top 5.