The 2005 Patriots.
Rodney and Light lost for the year in Pittsburgh. Bruschi out half the year recovering from a stroke. No more Ted Johnson, Roman Phifer, or Ty Law. Now Chad Brown, Monty Beisel, and Duane Starks. Sloppy ending in Denver. Kind of the lost year of the Patriots dynasty.
(Source: http://www.hulu.com/)