This one is too close to call. The legacy for all parties involved is largely important in each franchise’s history.
Super Bowl 42 was a massive missed opportunity for the Patriots — the 2007 Pats were the best team assembled in the Brady -Belichick era, and a 19-0 season would have culminated the greatest campaign in NFL history. The Helmet Catch still haunts Patriots fans to this day.
As for the Giants, they not only won their third Super Bowl in franchise history, but they recorded the greatest upset in NFL history and the greatest play in Super Bowl history. Not too shabby. Additionally, the game is the defining moment in Eli Manning’s career, and it allowed Giants legend Michael Strahan to retire a champion. Despite terrific Super Bowls vs. Buffalo, and the rematch vs. New England in 2012, this game remains the signature contest in the history of the Giants decorated franchise.
Super Bowl 51, however, represented a culmination of Brady and Belichick’s efforts. Five rings for Brady is the most ever by a quarterback, putting him over Joe Montana and Terry Bradshaw. Bill Belichick also set a record for most Super Bowl wins by a head coach. Throw in the Deflategate storyline, and the fact that the game was the greatest comeback in Super Bowl history, and you have a pretty killer legacy.
As for the Falcons, this could be a franchise defining loss if they don’t bounce back. While they have an incredibly talented and young team, few losses can be as crippling as this.
This category is by far the closest to call, but because of the magnitude of the victory for the Patriots, it takes the cake, only just.
Edge: Super Bowl 51, by the slimmest of margins.