Dick Butkus was the first name that popped into my head.
But then I started thinking of names like Lawrence Taylor and Jack Lambert.
One of my favorite was Steve Largent.
I know, you say that he was a wide receiver. But back in 1988, the Seahawks were playing the Denver Broncos at Mile-High Stadium. Largent caught a pass over the middle. Denver safety Mike Harden threw a right forearm to the left side of Largent's face, shattering the facemask, dislodging teeth and leaving Largent briefly unconscious and with a sprained left knee. Fourteen weeks later, the Broncos were at the Kingdome. Harden intercepted a pass intended for Brian Blades and headed up the sideline. Largent took off after him like a cruise missile and hit him so hard he fumbled. Largent recovered the ball. Revenge was sweet that day.
You can see the hit here:
http://www.seahawks.com/MMSec.aspx?vid=60&MMSecID=9