For the record, I remember quite well the "rivalry" between the Lakers and Celtics... Though as Garnett aptly put it, it's more of a history than a rivalry...
Look, we all come at this from different points of view - that's what is so great about sports... So I really don't expect anyone here to really understand the Boston-NY thing... This is more than a rivalry. It actually pits the cities against one another. Sports is just one of the MANY issues between these two cities. I grew up in the NY area and went to college 30 mins outside Boston. I still marvel at the conversations I witnessed between Boston and NY residents... Which city is cleaner, has better food, prettier women, better education, and even which city had bigger/stonger people (no lie). A battle like this is sio much more geographic in nature, and sports just fueled the hate!
In pure sports terms, there never has been and never will be a rivalry like the Yankees - Red Sox rivalry. 3 hours separates the cities... They have played in the same division for 100 years! The Yankees got The Babe from Boston! Same for Boggs & Clemens - who each won a World Series with the Yankees, having never done so with the Sox. The Sox, down 3 -0, came back and won 4 straight to finally break the jynx against the Yankees...
Lakers - Celtics? Ummm, yea - at one time they were the two most dominant teams in the NBA. But rivalry? I mean, does anyone in LA care what is happening in Boston, and vice versa??
I would buy a LA - San Diego, LA -San Francisco, heck, even a LA-Phoenix rivlary more than I would buy into a LA-Boston rivalry...