I live near Boston but was born and raised in central NY, and will never cheer for the Patriots out of principle. However, Tom Brady was the best QB to ever play before, during and after this game. His legacy is secured.
What Brady has accomplished in a league with a hard salary cap is absolutely unfathomable. He has both endless personal accolades and team achievements, and there's simply no one else that compares. Obviously he and Belichick have a symbiotic relationship; Belichick has never won a Super Bowl as head coach without Brady as his QB, and vice versa. Games are won and lost as a team; otherwise, Trent Dilfer would be more highly regarded than Dan Marino. But Brady has made a career out of elite play when it matters, and he's still been incredible during the regular season. He's not the best passer of all time; I'd personally put Aaron Rodgers and Dan Marino at the top of that list. But he is the best quarterback of all time.
Before Super Bowl XIX, John Madden was asked his opinion on Marino v.s. Montana, and he said: "Marino is the best passer I've ever seen, but if I want to win one game, I'm going with Montana." That throne now belongs to Brady. Brady's a Northern California kid that probably idolized Montana growing up...it's pretty incredible when you go on to exceed the exploits of your childhood idol, and that's exactly what happened.