Everybody always says the 1985 Bears but I believe the 2000 Ravens had the best defense of All-Time.
1) Best rush defense in NFL history. Gave up 970 rush yards total, 60.6 per game, 2.7 per carry, only gave up 5 rushing TD all season
2) Recovered 26 fumbles, double the 2nd ranked team in 2000.
3) 165 points against
4) Had a long stretch of games where they didn't give up a defensive TD
5) Dominated the Giants in the SB
6) Gave up 7 or less points in half of all regular season games
Let's look at their talent with 8 pro bowlers on defense, and 2 HOF guys.
DE Michael McCrary - 2X Pro Bowler, 1X All-Pro. guy had one of the best motors I can ever remember.
DE Rob Burnett - 1X Pro Bowler, had 2 more career sacks thatn McCrary.
DT Sam Adams - 3X Pro Bowler, huge space eater in the middle, wouldn't get pushed around.
DT Tony Sirigusa - Giant space eating meat ball in the middle of the line
DE/OLB Adalis Thomas - 2X Pro Bowler, 2X All-Pro
MLB Ray Lewis - 13X Pro Bowler, 10X All-Pro, quite possibly the best LB to ever play the game
OLB Peter Boulware - 4X Pro Bowler, 1X All-Pro
OLB Jamie Sharper - never made a pro bowl but was a very solid starter
(Pro Bowler Ed Hartwell came later)
S Rod Woodson - 11X Pro Bowler, 6X All-Pro, NFL 75th anniversary all-time team, one of the best safeties ever
CB Chris McCalister 3X Pro Bowler, 2X All Pro, one of the most underrated players of the last 20 years.
CB Duane Starts - Solid cover corner
S Anthony Poindexter - Solid hard hitting safety
Return man - Jermaine Lewis 2X Pro bowler, 2x All Pro
K Matt Stover made the pro bowler but K technically counts as offense.