Here is my list of the top 10 defensive lines in NFL history. I did a lot of research via pro football reference and watched NFL footage to put this list together. I took into account pass rush, run defense, how good the players were throughout their careers and how good they were in one particular year. Keep in mind this is just my opinion on a subjective topic and is not empirical fact.
Someone loves Merlin Olsen. The best D line ever was the Steel Curtain. Vikings were great as well
In my life time the Steel Curtain should be number 1. Not sure what the list is based on