I usually root for the underdog, so I hope the Giants win. There have only been two teams who have been 10+ point underdogs to win the superbowl. Those teams were the Patriots over the Rams in the first of their three superbowl wins, and the other team was the Broncos over the Packers (14 point underdogs) in one of the best superbowls ever. (imo)
Anyway, the Patriots are clearly the favorite in this matchup, but there have been bigger upsets before. That and the Giants gave the Patriots all they could handle in their regular season matchup. In order for the Pats to win in anoter game like that, Brady would have to have an amazing day, and he's been pretty lukewarm so far in the playoffs, espescially against an LT-less san diego.