Greatest 1 on 1 rivalries

I'd go Ali/Frazier, Magic/Bird, Wilt/Russell as my top three.

(Unlike the first two, Wilt/Russell was lopsided- the first two were very close.)
 
You've never heard of Irish Mickey Ward and Arturo Gotti?! Man those were some great fights!

Those fights were awesome!
I'm not a tennis fan, but my wife is and we watched the Wimbleton Mens' Final between Nadal and Feder last weekend and it was unbelievable!
 
Gene Tunney-Jack Dempsey Harry Grebb- Gene Tunney Sugar Ray Robinson-Jake LaMotta George Brett-Goose Gossage 1960 US hockey team VS the Soviet's in the Olympics. 1963 Dodgers VS the 2 time defending world series champs, the Dreaded Yankees. Willy Coyotevs the RoadRunner and my favorite The Wolfe vs the Sheepdog:D
 
Those fights were awesome!
I'm not a tennis fan, but my wife is and we watched the Wimbleton Mens' Final between Nadal and Feder last weekend and it was unbelievable!


Ditto, it truly was unbelievable. Both my wife and I were really into the end of that match. Tennis is a true one-on-one sport, that's why my all-time rivalry has to come from this sport (boxing is in there as well). I pick Navratilova/Everett as my all-time rivalry with any combination of McEnroe/Connors/Borg close behind.