Piecing together an elite NFL defense is incredibly difficult. Talent is most important, but a truly dominant unit needs a collection of leadership, depth and intangibles too.
During the last two decades, two teams in particular boasted a legendary defense. When this discussion comes up among NFL fans, the conversation quickly finds its way to both the 2000 Baltimore Ravens and 2002 Tampa Bay Buccaneers.
However, the 2013 Seattle Seahawks and 2015 Denver Broncos typically aren't far behind. Plus, a mid-2000s unit deserves more attention than it usually receives.
While this ranking is subjective, the choices are focused on a defense's performance during the regular season.