The best rivalry in the NFL the past 20 years has been between the Pittsburgh Steelers and Baltimore Ravens. They've both been so good for so long that every game has mattered, and AFC North supremacy has usually been on the line. 

Both teams have won Super Bowl during that time under coaches John Harbaugh (Baltimore) and Mike Tomlin (Pittsburgh). But this week, both coaches are gone after middling seasons and both franchises are looking for new coaches.

What an incredible run it's been. They've met 44 times on the field from 2007 on, the second-most showdowns in NFL history behind only George Halas of the Chicago Bears and Curly Lambeau of the Green Bay Packers from 1921 to 1953.