8. L.A Lakers vs. Boston Celtics (Magic Johnson vs. Larry Bird)

Background
No 2 teams dominated the NBA in the mid-1980's like the Lakers and the Celtics. They were the 2 teams in the NBA. They met in the NBA finals in 1984, 1985 and 1987. And each team had their own franchise superstar, Magic Johnson and Larry Bird - the two players of the 1980's. Their personal rivalry actually dates back to 1979 when Magic and Bird met in the NCAA finals.

Why This is/was a Great Rivalry
Not so much a great rivalry anymore, as the Celtics have not been much more than lame ducks since Bird retired in the early 90's. But in the 80's if you wanted a marquee game, you wanted Lakers-Celtics. And if you wanted a marquee battle, you wanted Bird-Magic:

http://www.youtube.com/watch?v=7B4IoQoCfrQ

It's generally accepted that these two players saved professional basketball in the early 80's. They came along and injected life back into a dying sport. The rivalry between these two players and these two teams created excitement where there was none before.