6. Happy Gilmore vs. Shooter McGavin

Background
Seriously...do I need to explain this one?

Happy can hit a golf ball a country mile, his grandma needs money to save her house, Happy joins PGA tour to raise money, Shooter is jealous of Happy; buys grandma's house, Happy and Shooter play final game for possession of the house.

There, I've just ruined the movie for you, but do yourself a favour and watch it anyway if you've never seen it - and if you have watch it again.

Why This is a Great Rivalry
Classic good vs. evil, David vs. Goliath, underdog situation. Plus you've got Sandler in his absolute prime (but that doesn't really make it a great rivalry, just a great movie). And as if that wasn't enough you've got Apollo Creed as Happy's golf coach. And then just to top it off, the best rhyme fight in cinematic history:

http://www.youtube.com/watch?v=tgH4ECnSRKI