Defense is separated into three parts: the line, line backers, and the secondary.
For those who don't know, the secondary consists of the defensive backs, cornerbacks, and safeties. The secondary is the heart of the team's pass defense, but sometimes can take the role of pass rushing and run defense.
The rankings will be based off the performance of the players last year, the improvements each secondary has made over the offseason, and the improvements each individual player has made.
No. 7: Denver Broncos
Nine out of 10 people never saw this coming. For years the Broncos' defense has been a laughing stock, and they've rolled over on their backs so opposing teams could walk all over them.
But times have changed.
While their line and linebackers remain horrendous as always, their secondary has taken great strides.
They are anchored by new, strong safety Brian Dawkins, who not only provides strong leadership to the Broncos' shattered locker room, but a dangerous threat in the secondary. He may be getting old, but he hasn't run out of fuel yet.
Cornerback Champ Bailey is getting old too, but still has gas in the tank. When healthy, he is a danger to anyone unfortunate enough to be covered by him. The No. 2 man is Andre Goodman, who is coming off a great year in Miami, where he racked up five interceptions.
Free safety is their weakest spot, as Renaldo Hill had a good three interceptions, but an unimpressive four pass deflections, the lowest for free safeties in 2008.
No. 6: Washington Redskins
While DeAngelo Hall may have been grossly overpaid, it is good to have him on the defense. He is a strong player, and an effective corner. He finished last year with five interceptions, a very good number considering the NFC leader had seven.
Carlos Rogers is the most underrated player in the secondary and on defense. While he only had two interceptions, he had 56 tackles, and 24 pass deflections, three more than Hall.
The key cog in this unit is free safety LaRon Landry. While his stats may not be as good as Hall's, he makes a bigger impact consistently—something Hall doesn't. Strong safety Chris Horton had two sacks and three interceptions, but lacked consistency.
No. 5: Arizona Cardinals
The Cardinals had a mediocre defense in the regular season, allowing 40+ point games against the Jets, Patriots, and Eagles. However, they showed their might in the post season, especially in the secondary.
The Cardinals posted nine interceptions, with seven of them from defensive backs. Dominique Rodgers-Cromartie led the secondary as a rookie. He even put up a 99 yard interception return for a touchdown, just nine yards short of the record set by Ed Reed that year.
Many, including me, believe he was robbed of Defensive Rookie of the Year.
Also at cornerback is Bryant McFadden, who came from Super Bowl Champion Steelers. McFadden was one of the most underrated corners in the league, and arguably the best corner on the Steelers loaded roster.
At free safety is Antrel Rolle, the younger brother of Ravens corner Samari Rolle. It seems skill runs in the family, as Rolle posted 89 tackles and an interception last season. He also had one postseason interception, which he returned for 47 yards.
The Cardinals also have one of the best strong safeties in the league in Adrian Wilson. Wilson may not have had the best numbers in 2008, two interceptions and two forced fumbles, but he is the most consistent member of the secondary in front of Dominique Rogers-Cromartie. At 29, he isn't exactly young, but he has his best years ahead of him.
No. 4: Pittsburgh Steelers
The Steelers were the number one defense last year, and it turned out defense still wins championships. Their roster is absolutely loaded with talent and leadership, and it shows in their performance.
Free safety Ryan Clark is the most underrated player in the NFL, in my opinion. He is hard hitting and has hands better than what his stats suggest. He might just be the hardest hitter in the league, and if he isn't, he's definitely top-10.
Just ask Wes Welker and Willis McGahee, both extremely talented players who had the misfortune of being in his way, quite frankly. Some hits make the crowd cheer: Clark's make the crowd silent and shocked.
Ike Taylor is the No. 1 cornerback for Pittsburgh, and is one of the best cornerbacks the Steelers have had since Rod Woodson. He only had one interception, but he did have 65 tackles and 14 pass deflections.
What puts Pittsburgh so low is the departure of cornerback Bryant McFadden to the Cardinals.
His departure will make a bigger impact than people suggest. Deshea Townsend will replace him, but he only played a limited amount of time, and despite putting up two picks, he only had 20 tackles.
Then there is Troy Polamalu, the best strong safety in the league. He can do it all—sack, tackle, pick, safeties. You name it, he can do it.
Polamalu is all over the place. One play he is pass rushing, the next he makes an interception.
Troy tied for second most interceptions last year with seven, behind Ed Reed.
No. 3: Baltimore Ravens
The departure of Jim Leonhard, the strong safety who went from a nobody to a star, makes people a little worried about the Ravens' secondary.
However, people fail to see who is starting next year—Dawan Landry, the older brother of Redksin safety LaRon Landry.
Landry had an astounding rookie season in 2006, and followed it up with a great 2007 campaign. His 2008 season was cut short when he went down with a neck injury, placing him on IR. Expect him to rebound greatly.
The two starting cornerbacks are Fabian Washington and Domonique Foxworth. What they lack in size, they make up for in speed. They may just be the two fastest cornerbacks in the league.
Last year, Washington had a great season, with a career-high 15 pass deflections and 34 tackles, all in 12 games. Foxworth, a Baltimore native, comes from the Atlanta Falcons. There, he posted 38 tackles, 15 pass deflections, and one interception.
Quite frankly, Ed Reed may be the greatest safety to ever play the game of football. No one knows how he does it. Last year, he had four games in which he had two picks, and he returned two for touchdowns over the course of the year.
He set the record for longest interception return for a touchdown with 107, breaking the record of 106 yards, previously set by Ed Reed.
He also had a sack and forced a fumble, which he returned for a 20-yard touchdown. He led the league in interceptions for the second time in his career (with 9) and interception yards(with 264).
He flexed his muscles again in the postseason, intercepting two passes, one of which he returned 64 yards for a touchdown.
A tip to all NFL quarterbacks—don't throw the ball anywhere near Ed Reed.
You'll regret it.
No. 2 Green Bay Packers
Sorry Nmandi Asmougha, Charles Woodson is the best cornerback in the league. He had an NFC-high seven interceptions, along with 50 tackles, 17 pass deflections, and three sacks. He may be 32, but he isn't showing any signs of slowing down.
In fact, he is in his prime, and it will likely stay that way for a long time.
The other corner is the young Will Blackmon. At 24, he is still developing, but will soon be doing great things on the field as he gets ready to enter his prime. He forced two fumbles and recorded 35 tackles in 2008.
Safety Nick Collins is the best free safety in the NFC without a doubt. He had a career year, posting seven interceptions, one forced fumble, 15 pass deflections, and three touchdowns.
He is only 25 and is only getting better. Expect greater things.
Maybe even Ed Reed or Troy Polamalu numbers.
Joining him is Atari Bigby, who posted solid numbers for someone who only played eight games. Imagine what kind of damage he could do in 16. He posted 21 tackles and an interception last year.
No. 1: Tennessee Titans
The roster for the Titans is full of stars who had breakout seasons in 2008. Cortland Finnegan, Chris Hope, and Michael Griffin are among those.
If Michael Griffin knocked on your door, 90 percent of people whouldn't know who he is. But opposing quarterbacks know who he is. At free safety, he made his mark as one of the young, rising stars in this league. Griffin had an astounding 75 tackles and seven picks, tied for second most in the league.
Playing next to him is strong safety Chris Hope.
Hope had another great season, one of many in his career. He had four interceptions, a forced fumble, and a sack—the first of his career. He was voted to the Pro Bowl with Michael Griffin and Cortland Finnegan.
Speaking of the latter, Finnegan cemented himself as one of the best corners in the league. He had five interceptions, one of which he returned 99 yards for a touchdown, nine yards short of Ed Reed's record.
He also has 70 tackles, a sack, and 17 pass deflections. Pretty good for a cornerback.
He joins Nick Harper, who had four interceptions last year.