It seems ESPN has posted a poll on the top 10 "ToughGuys" in the NFL. Urlacher is on the list but one gaping omission to me is the absence of Olin Kreutz. This guy has always been mentioned as one of the meanest SOB's on the field. If there was a write in I would definitely include him.
The list of 10 from which you can vote:

1.  Steve Hutchinson, OG, Vikings
   
2.  Ray Lewis, LB, Ravens
   
3.  Donovan McNabb, QB, Eagles
   
4.  Steve McNair, QB, Ravens
   
5.  Troy Polamalu, S, Steelers
   
6.  Will Shields, OG, Chiefs
   
7.  Sean Taylor, S, Redskins
   
8.  Brian Urlacher, LB, Bears
   
9.  Hines Ward, WR, Steelers
   
10.  Al Wilson, LB, Broncos