I believe we have already covered the top three pretty well, but rounding out the top 5-10 gives a little more leeway to talk about other perfromances
To throw out another great Defensive performance that deserves recognition,
Lofa Tatupu in 2005.
This rookie came in and was pivotal in the Seahawks making their first Superbowl appearance. While 104 tackles, 4 sacks and three interceptions is a good year for a good player, my recollections watching that season had Lofa directing traffic and coordinating the Defense to help generate their 50 total sacks, allowing only 271 points, and producing games which showed team level defensive domination that would not be seen until the current era.
While the stats might not show as one of the best ever - they were certainly excellent, but not epic - the stats in combination of his leadership and performance on the field puts his 2005 year up there as one of the best individual defensive performances in my mind.
As a comparison, the 2013 Superbowl winning team allowed 231 points -not all that far off. We may overlook the outstanding defensive performance of 2005 because we are now too accustomed to seeing league-leading levels of defensive play.