What is the NFL's Equivalent Rivalry?

Bears-Packers was the first one that came to mind for me. You have to remember that MLB and NBA play a ton more games, so by default there's more history in those leagues than the NFL.

For more recent ones and to avoid homerism, I'd say the Ravens-Steelers has provided some of the most entertaining, physical games and would be on the short list for the best of this generation.