There are 3 truly iconic rivalries between wrestlers (Austin vs McMahon is pretty epic too) and those are Hogan vs Savage, Hitman vs HBK, & Rock vs Austin.
However there are some others that are pretty damned amazing, and that happened a long time ago, or were simply not publicized like they could have been were they in the WWE or WCW during the 90's. Those older ones are the ones I believe should be focused on as even a lot of us older fans missed out on them and have grown up hearing about how incredible they were.
Jerry Lawler vs Andy Kaufman
Has anyone NOT heard stories about this one? But did anyone actually see it? I haven't, I only know just a little more than what I saw from the movie Man in the Moon with Jim Carry. This is one of the most publicized feuds of all time, and yet it was so long ago, even an older fan like me hasn't seen it.
Raven vs Tommy Dreamer
Here's another one of those storied rivalries. Most every account of this rivalry states that this is the feud that put ECW on the map and defined what the company was about.
Hulk Hogan vs Andre The Giant
I saw Wrestlemania 3 live on PPV, but that was the climax to the story, I saw none of the buildup. And everyone knows that Hogan slams Andre is one of the, if not the very most memorable event in pro-wrestling history.
Peter Maivia vs. Superstar Billy Graham
Here's a rivalry I've heard very little about, only that it was a good rivalry. But knowing Peter Maivia is the grandfather of The Rock and a HoFer and a figurehead in wrestling to rival Stu Hart as the grandfather of so many Samoan wrestlers. Then, knowing that Superstar Billy Graham is the guy whose gimmick everyone from Jesse Ventura & Hulk Hogan, to HHH, Stone Cold, & Big Pappa Pump adapted as their own, who is also a HoFer and well known to be one of the most charismatic characters of all time. How could you go wrong with a DVD documenting their feud?
Mr. T vs. "Rowdy" Roddy Piper
This was part of the main event of the first ever Wrestlemania, and the main event again at the second Wrestlemania. Their feud was one of the highest profile to date, with stars like Cindi Lauper, and spots on MTV. Does anyone remember seeing this? Anyone? This is one to watch, for certain.
Sgt Slaughter vs. The Iron Sheik
Does anyone know WHY Sgt. Slaughter was one of the biggest heels of his time? It was because no one would have ever believed Slaughter was capable of joining Iron Sheik, who was one of the biggest heels of all time, after having spent so much time feuding.
Ric Flair vs Sting
Here's a rivalry that made WCW. In the WWF you has Hogan vs Savage, but in the WCW you have Flair vs Sting, and in some ways it was the better rivalry. But again, who's ever seen this feud?
Ric Flair vs Ricky "the Dragon" Steamboat
After putting on the match of the year at WM3 he left (due to extenuating circumstances) and joined the WCW and then put on match after match that was easily it's equal if not better vs Ric Flair. Their rivalry is legendary, and yet another one few have seen.
Tito Santana vs. Greg Valentine
Everyone knows that the Intercontinental Championship title used to be nearly as prestigious as the WWF title. Tito Santana & Greg Valentine fought like animals over this title which resulted in a cage match that is considered one of the best cage matches of all time. Their feud is one of the best feuds for the IC title of all time, and cemented both of their careers as Hall of Famers. And like all the others I'm listing, there are so few these days that have seen this feud.