As is usually the case leading up to the Super Bowl, most of the attention in recent days has focused on the opposing quarterbacks. Is there one great game left in Peyton Manning, and will this be the last time we ever see him on a football field? Is Cam Newton about to win the MVP, and where on earth did he get those pants? While the quarterbacks have been generating headlines, though, the defenses should not be forgotten. Denver's unit, in particular, carried the Broncos to the Super Bowl, ranking as the NFL's best defense this season in Football Outsiders' rankings, while the Panthers finished second overall.

Using Football Outsiders' DVOA rankings (you can find the methodologies here), we can analyze the five best defenses to make the Super Bowl going back to 1989. So while the database does not include stalwarts such as the 1985 Bears or the the great Steelers and Dolphins defenses of the 1970s or the Packers of the 1960s, this Broncos team did make the cut.

These rankings reflect regular-season performance only, though our commentary here will discuss each team's postseason fortunes. With that in mind, here are the best defenses we've ever measured among Super Bowl teams.

You know your defense is something special when they name an entire scheme after your team, and the Tampa 2 scheme that coordinator Monte Kiffin developed in Tampa Bay is still used throughout the league today. Though the Bucs had been a great defense for several years under Kiffin and Tony Dungy, it wasn't until Jon Gruden replaced Dungy as head coach in 2002 that the Bucs could field an offense good enough to win a championship.

Still, it was the defense that was dominant for these Bucs. Led by stars such as Warren Sapp, Simeon Rice, Shelton Quarles, Derrick Brooks and John Lynch, the Buccaneers led the league in points, yards, yards per play and turnovers. They were especially dominant against the pass, giving up only 10 touchdown passes while collecting 31 interceptions, both tops in the league.

Led by that defense, the Buccaneers went 12-4 and won the NFC South. They opened their playoff run with a 31-6 beatdown of San Francisco, then traveled to Philadelphia to beat the Eagles 27-10 in the conference championship before crushing the Oakland Raiders 48-21 in Super Bowl XXXVII. In the process, they limited Jeff Garcia, Donovan McNabb and then-MVP Rich Gannon to a combined 54 percent completion rate, with two touchdowns and nine interceptions. Those two touchdowns both came with the Bucs up by at least three scores in the second half of the Super Bowl.