I say Steelers/Ravens because they are at least competing against each other for a division title, this year notwithstanding. Manning/Brady would be in the mix; despite the results, they seem to always at least be competing for the Conference.
Steelers Ravens is #1 and Jets Pats is close. One that's quietly emerging is Ravens Bengals. They've played a ton of really close, great games in the last couple years and every game in the AFC north is essentially a rivalry.
There was a time back in the mid 80's where it seemed like the Raiders had a rivalry going with every team they played. Fun team to watch and even funner to party with. I loved the old AFL.
