Here's my take, bluejacket (and I echo your sentiment - no offense intended to anyone)...
There are so many factors in competitive sports that affect the outcome of a particular contest. No question - luck is part of it; it's that right time, right place thing. From my perspective and my pre-game call for the Giants to win, it came down to matchups - and watching both teams as they made their way to the super bowl. Did I KNOW conclusively that the Giants would win - no. Did I have a very strong hunch that they could? Absolutely. From there, it's the intangibles that determine a win or loss. If, like you say, on that last drive any of the almost-picks became interceptions, game over. If Manning takes the sack on 3rd and long instead of completing a very unlikely pass for a first down, their chances would have been slimmer. The Patriots are talented, no question. Best team in football? I dunno. I don't know that you could measure that. The Eagles almost beat 'em - so did the Ravens. Did either one go to the playoffs? So - how would that factor in in determining the "best in football" tag?
In the end, yup - the Super Bowl is one game. It definitely does not make the Giants the best team in football automatically, but it gives them the best title, given the importance of the Super Bowl.
Regardless of anything else, like you said - it was fun to watch.