Yankees vs Red Sox

The oldest and most bitter rivalry in American professional sports, dating to 1901. The "Curse of the Bambino" — Boston selling Babe Ruth to the Yankees in 1920 — haunted the Red Sox for 86 years until they won the World Series in 2004 (coming back from 3-0 down against the Yankees in the ALCS, the only team in MLB history to do so). The 2003 ALCS Game 7 (Aaron Boone's walk-off homer) and the 2004 ALCS (Dave Roberts' steal) are among the most-watched baseball moments ever. The rivalry has generated an estimated $1 billion+ in media value and keeps both franchises among the most valuable in sports.