Brady > Manning. And at this point in their respective careers, it's not even debatable.
Manning came into the league coronated as the next great QB. He's been given great offensive weapons since his days on the Colts and even more so now with the Broncos. Since then, he has set (and broken) numerous records and made himself the darling of QBs. Ironically enough, it was the defensive that led Manning to his lone Super Bowl victory.

And even still, he has a losing record against Brady and the Patriots.

Nonetheless, he'll go down as the GOAT regular season QB. And that's no small feat at all. But his playoff record (a losing record and the most one-and-dones for any playoff QB) and that blowout of a SB game against the Seahawks magnifies the fact that Peyton STRUGGLES in the big games.
Brady on the other hand, was drafted in the 6th round and came in unheralded. Got his big break, compliments of Mo Lewis. Although Brady had a great defense, he has shown time and time again that he does the MOST WITH THE LEAST. If you gave Brady any of the receivers that Peyton enjoyed in his career (any combination of Marvin Harrison, Marshall Faulk, Reggie Wayne, Edgerrin James, Dallas Clark, Marcus Pollard, Demaryius Thomas, Julius Thomas, Emmanuel Sanders), Brady would have EASILY had more SB victories.

And even with the disparity in offensive weapons, Brady still broke records, was named 2x league MVP, SB MVP, went UNDEFEATED during the regular season in one year, led his team to numerous SBs and AFC Championships, and owned Peyton

when they went face-to-face.
Brady overachieves and wins. Peyton underachieves and loses, despite having everything handed to him on a gold platter.
Stans lie. Numbers don't. Rings don't.