Yankees vs Sox? Duke vs UNC? Ohio State vs Michigan? Cowboys vs Redskins? Dodgers vs Giants? The entire "black and blue" division? Nothing in the world can top a great sports rivalry. In order to find out what makes a great sports rivalry we must first determine the necessary factors that make two teams hate each-other so much that every time the schedules are released every fan on earth circles every game in which they will play each-other.
History- Every noteable feud needs an epic past. When you hear that two teams have played so much, they know each-other so well, and have such a strong ; you tend to pay more attention.
Hatred- Two teams have to despise each-other so much that not only do the players know it but the media and all the fans do as well. If a casual fan sees these two teams playing they tend to stop and watch in awe and amazement.
Big game situations- When the Redsox play the Yankees in a game seven of the ALCS, it's a huge deal. When the Cowboys and Skins lock up with the division title on the line, it's a huge deal. When the ACC crown is up for grabs and the last two teams standing are the Blue Devils and the Tar Heels, it's a huge deal.
So with that criteria in mind what is the end all be all sports rivalry? In my opinion it is Yanks vs Sox hands down. Not only do they play the in the oldest professional league of the "big three" in America they also flat out can not stand eachother. Every season they are battleing it out for pride and for a championship. The resurgence of the Bo Sox has only brought even more credibility to this amazing rivalry. Although it started with Babe Ruth, when i think of this rivalry i am always haunted with Aaron " bleeping" Boone's monster homer, Pedro throwing Don Zimmer to the ground, or even the epic 2004 collapse by the Bronx Bombers. With a rivalry with so much passion and intensity how could you go wrong?