I am nominally a Giants fan. This is because growing up, Lawrence Taylor was playing for the Giants, and he was the most famous Carolina football alumnus at the time. It also didn't hurt that at that time in North Carolina, everyone was a Redskins or Cowboys fan, and I am ornery and contrarian at the best of times.
I say nominal because during the 2000's I drifted away from the Giants, to the point that when they won the Super Bowl in 2008, I backed away from being referring to myself as a Giants fan. I hadn't suffered in the wilderness between 2001 and 2007; I didn't deserve to bask in the SUper Bowl win. I found that my NFL rooting interesting was geographically dependent. The further I was from North Carolina, the more of Panthers fan I was; the home state needed my help. The closer I am to the East Coast, especially in DC surrounded by those Cowboys and Redskins again, I revert to the Giants.
But generally in the Super Bowl I root for the team with the most Carolina alumni. This year this dovetails nicely with my Giants fandom, as Hakeem Nicks is one of the main offensive weapons for New York, while Marvin Austin is on the injured reserve list for the team as well. Oh, and Austin's still a little bitter, judging from this tweet:
where is @cmiller05 wanna take him out to dinner he help me get here #NCAAinvestegator
Sigh. (Chance Miller is the NCAA's Assistant Director of Agent, Gambling and Amateurism Activities.)
Carolina's been in a bit of a Super Bowl drought. The last team to win the game with Tar Heel alumni was the Pittsburgh Steelers in 2009, with Willie Parker, Jeff Reed and Greg Warren. Only Warren is still with the Steelers. UNC has had an alumnus play in the Super Bowl every year going back to at least 2002 though.
So if you don't have a vested interest in today's game, I'd urge to pul for the Giants. Don't do it for my sake, but for Nicks, who has played well enough over the past few years to deserve a Super Bowl ring. And it'll annoy the Patriots fans.