The top 5 were (if I remember correctly):
1) The 80's Saints - Mills, Swilling, Jackson, Johnson
2) The 70's Steelers - Ham, Lambert, Russell
3) The 80's Giants - Banks, Reasons, Carson, Taylor (honestly, how many of you heard Pat Summerall's voice right now when you read it?)
4) The late 60's Chiefs - Bell, Lynch, and Lanier
5) The 80's Bears - Marshall, Singletary and Wilson
In my opinion, you could rank any one of these units #1 and make a strong case for it. I personally thought they (NFL Network) would go with the Bears #1, the Steelers #2, and the Giants #3. I was a little surprised to see the Saints corps listed that high, but they made a compelling case for them.