Manning's 2004 trumps Brady's 2007*

Again, notice the asterisk. Tom Brady may have thrown 50 touchdown passes to set a single-season record* in 2007. Peyton Manning held the legitimate previous mark at 49, breaking Dan Marino's mark that had stood for 20 years. But there are some facts worth noting that in this Patriots-hater's mind make Manning's record-breaking season a more impressive one.
Consider, first of all, that having the class that he does, Tony Dungy sat Manning in the fourth quarter of a number of blowouts to let backup Jim Sorgi take some reps. Bill Belichick, meanwhile, not only usually left Brady in, but once even brought him back out to throw one more scoring pass just to rub it in Miami's face because the winless Dolphins got to within 21 points.
Unlike when New England went for the jugular with nothing on the line other than a record in the final game against the Giants (who won the only matchup between the teams that mattered last season), Dungy pulled Manning after just one series of the Colts' season-finale in Denver. Sitting on 49 against a defense that just two weeks prior had been scorched for 45 points by a sub-.500 Chiefs team, Manning easily could've topped 50. Even with Marino's record gone, Manning should have figured it wouldn't be safe with cheaters still on the loose. But still, Dungy is a class act and wanted to make sure his top-notch players were healthy when the Colts met the Broncos again the next week in the first round of the playoffs.
Brady undoubtedly knew what plays the Jets were running in the 2007 opener, and it wouldn't be much of a shock if he caught some illegal video footage of some of the other opponents the Patriots played. There were games, like the aforementioned Miami contest and a game against Washington the following week in which, despite a massive lead, Brady was still in slinging it against a hapless, defeated foe. Brady connected with Wes Welker in the Washington game for a score to make it 45-0 in the fourth quarter. The pint-sized Welker, beneficiary of double- and triple-teams on Randy Moss all year, spiked the ball like he had just won the Super Bowl (something he will hopefully never experience). What did Marvin Harrison and Reggie Wayne do after a touchdown? Hand the ball to the official, even if the score put the Colts ahead in the fourth quarter.
All told, Brady maxed out with 50 scoring tosses. Manning probably lost more than a game's worth of action to rest because many of the Colts games that year were out of reach early. No need to rub it in, right? But had slimy Belichick been pulling the reigns, Manning's record would probably still be standing in the mid-50s.