THE PITTSBURGH STEELERS!
On a serious note, what you are really comparing is the difference between the level of skill in the AFC and NFC. The AFC has many better teams Than the NFC IMO, and the level of competition seems higher in the AFC. In the NFC there are few teams that are really good and many that aren't so good.
When you compare who lost to who, the Colts have lost to better teams like the Jets, while the Saints lost to lower end teams like Tampa Bay (That was a shocker). The colts rested Manning and they lost, the Saints played Brees and they still lost.
When you compare defenses, you can see the big difference. The Saints made it to the Superbowl on their high powered offense putting up huge numbers against teams like the Giants, but have allowed many points to be scored on them. The Colts do not blow out teams by 30+ points, but they win by controlling the pace of the game and allowing fewer points.
Those points just prove why the Colts are the obvious favorites in this game, however I would like to see Drew Brees take the first Superbowl to New Orleans.