What is the greatest rivalry in sports?

Pakistan Vs. India is one of the greatet rivalry's in the world.

It depends on where you live and what the sport is. Here the Toronto Maple Leafs and the Montreal Canadiens have the longest rivalry ever - since the Original Six hockey teams in the NHL. Go Leafs!

In Chicago, one of the big ones is Cubs vs. Sox.

Well here in the US i think the Yankees vs Red Sox is giant. But probably the Brazilian soccer team vs Argentina's soccer team is big too. There might also be a big rivalry in Europe with the soccer leagues. I guess they'll never be a right answer to this question. There have been wars between nations, over the outcomes of a single game. Can't forget history now.

pakistan vs india nothing can get hotter than that