The goal of any football game is simple: outscore the other team. Many teams try to do so with high-powered offenses, and most of those teams are unsuccessful.
The best way to outscore the other team is by stopping the other team from scoring at all. Those are the teams that you consistently see atop the BCS rankings and the teams that end up playing in the championship game come January.
The SEC has generally dominated defense, and they still do for the most part, but other teams have pushed their way into the top defense discussion.
Here is a list of the nation's top five defenses.