There are many ways to define a rivalry, and the NFL is full of them.
There are team vs. team rivalries, coach vs. coach, player vs. player, team vs. player, coach vs. player, owner vs. player and even some rivalries that just remain in the head of one person.
In this slideshow, nothing is off limits as the NFL world (hopefully) gets ready to end this lockout nonsense and get back to the business of professional football.
Included here are both rivalries and feuds. Some are intense, while others are just insane.