I have to root for New York. I have a good friend from Jersey who is a huge Giants fan. Using the same logic, I have rooted for Pittsburgh the last two times they were in the Super Bowl. So I have to root for New York.
That being said ... If New England wins, they will have completed the most impressive season by any (American) professional sports team. They will not be the best football team ever. That's because of parity. You just can't assemble talent like you could just 10-15 years ago. Of course that is part of why their season will be the most impressive ever. They don't have overwhelming talent across the board, like say the 49ers and Cowboys of the early-mid 90's. They may have the best offense ever. I can't remember a team that could stretch the field horizontally and vertically like they do.
Anyways ... go New York!