New Orleans vs. Indianapolis - Two very dominant teams here. Both are #1 seeds, and both only lost games after they had clinched pretty much everything. There's no home field advantage in the/this Super Bowl, and both teams were an impressive 7-1 on the road. However, while both won at Miami in the regular season, New Orleans did so by 12 points (46-34), compared to Indianapolis' more modest 4-point victory (27-23). In terms of overall record, Indy was one game better, and their playoff win against New York cements the idea that their regular season loss against the Jets was meaningless. The Saints have the stronger and more balanced offense (but the Colts are still great), while the Colts have the stronger defense (in relative terms; we're really comparing an average defense to a bad one). Against common opponents (where the Saints and Colts curiously had identical home/road alignments in all their regular season match-ups), I'd give the Saints a slight edge, though it's kinda inconclusive. Both teams beat Miami and New England, but the Saints more strongly. Both teams both lowly St. Louis, but the Colts did so with considerably more dominance. The Saints beat the Bills and the Jets, whereas the Colts lost to both of them. However, timing is very important here, as these 2 losses were Indianapolis' last two regular season games, when they had wrapped up everything and were resting their starters. So not much meaning in these losses, especially given the aforementioned playoff vengeance against New York. Then there's the Arizona Cardinals, whom Indy beat comfortably on the road in the regular season, and N'Orleans beat even more comfortably at home in the playoffs. As stated before, comparing the teams' performances at Miami is probably more relevant than simply comparing all their common opponent match-ups. Though both teams won, I like New Orleans' victory more, particularly their offense's ability to score points -- but their defense didn't play so hot.
Both teams have a high-powered offense, a deep and athletic receiving group, and a very talented quarterback. Peyton Manning and Drew Brees were very similar in yards, touchdowns, and completion percentage, but Brees had a 10-point stronger QB rating, and a considerably better touchdown/interception ratio. Then again, Manning (or arguably the Colts' o-line) was considerably better than Brees (or the Saints' o-line) at avoiding sacks, and not giving up fumbles. Peyton Manning and the Colts have won a recent Super Bowl -- scoring 29 points against a smothering Bears' defense -- so they have an experience advantage over the Saints and Brees, and simply having been in this situation before should give them a comfort edge. Both New Orleans and Indianapolis are dome teams accustomed to noise, and great road teams. The Saints' Sean Payton has 2 more games of NFL experience head coaching in the playoffs than does the Colts' Jim Caldwell, though the latter has certainly proven he's quite capable.
As Deathlike2 has said, a hobbled Dwight Freeney in the Indy defense could be impactful, as he was very dominant with 13.5 regular season sacks. On the other side, if Jeremy Shockey -- who had 569 receiving yards in the regular season -- isn't able to play at decent speed, that leaves Drew Brees one less weapon (though he still has 3 wide receivers with massive yardage, and one tight end with solid yardage).
The Saints' defense couldn't stop Minnesota from marching the field, yet they contained a potent Cardinals' offense to 14 points the week earlier. One difference between those NFC foes was that Arizona had a weak running attack -- almost as bad as Indy's 32nd ranked one

. Now, the Colts' offensive line is better than Arizona's (and Minnesota's, based off sack stats), but the predictability that the offense will pass the ball could work against them. The Saints, meanwhile, are very balanced offensively with their strong running game.
I agree with the consensus view of this contest being a shoot-out, but damned if I know whom to pick. I'm favoring Indy, because their defense rose to the occasion in the playoffs, and the team has been more dominant than the Saints in recent years, including having a Super Bowl victory.
So Colts, 34-31. (I flipped a nickel over a dozen times to "confirm" this pick, to give you an idea of my confidence here. :/ )