1986 Jim Crockett Promotions is probably the best wrestling promotion and wrestling year that I have ever seen. As far as territories in general I would recommend Mid Atlantic(which is basically Jim Crockett), early 1980s Georgia Championship Wrestling, World Class Championship Wrestling and the Memphis territory.
Also, I think the AWA is another treasure gem. (especially late 70s to mid 80s)
I don't know if Mid-Atlantic in 86' is the best overall, because I haven't seen everything from that year, but at the very least it's in the top 5 from what I've seen. Mid-Atlantic in 86' is really what wrestling is all about, IMO. Wrestling was still protected enough and presented as legitimate, so it always felt like real stakes where on the line, while it wasn't SO protected that the matches weren't exciting, the characters were still over the top and entertaining, just all around it was the sweet spot for wrestling.
Here is the best stuff from Mid Atlantic in the 1980's and WCW in the early 90's that I think you need to make priority viewing:
1. The Ricky Steamboat/Jay Youngblood vs Sgt. Slaughter/Don Kernoodle tag team titles feud, culminating in the unbelievable cage match in Greensboro, which is one of the top 5 best tag matches I've ever witnessed. This entire feud was booked damn near perfectly, you simply HAVE to see it.
2. The Rock n Roll Express vs The Fourhorsemen (Ole and Arn mostly) feud that culminates in another fabulous cage match for the tag titles, this time at Starrcade 86'.
3. The Tully Blanchard vs Magnum TA feud. I can't say it definitively, but off the top of my head this MIGHT just be the best singles feud ever done in Mid Atlantic, maybe the best feud PERIOD. It was that good. Real life animosity, Magnum was married to Tully's ex-wife and raising Tully's kids, mixed with picture perfect booking and incredible realistic/brutal matches make this one of the best feuds of all time. The blowoff, an I Quit Cage match at Starrcade 85', is one of the top 5 matches of that entire decade and one of the top 10-15 best matches I've ever seen. Needs to be seen to be believed.
4. Ricky Steamboat vs Ric Flair, THE iconic feud of the era along with Dusty/Flair, these two feuded on and off from the late 70's, all the way through the 80's and into the early 90's, and you won't find a single match that isn't good, if not GREAT. Don't need to spill anymore ink, if you know wrestling you've heard of the legendary Steamboat/Flair feud/matches and know what kind of magic you are in store for.
5. Midnight Express vs The Fantastics; Midnight Express vs Rock n Roll Express, Midnight Express vs The Road Warriors. For my money the greatest tag team of all time is the midnight express. Whether it was the Eaton/Condrey or Eaton/Lane iteration, they were the gold standard as far as tag teams go. For the best matches, go with their Fantastics feud. For sheer pandemonium, incredibly heat, and iconic matches go with the Rock n Roll feud. For big time, big money, rock the house matches go with the Road Warriors feud. Or better yet watch them all, and throw in the Midnight Express vs Southern Boys GAB 90' match, as that's my 2nd favorite tag match ever.
6. Dusty Rhodes vs Ric Flair. To put it simply, the best mic work done in the history of wrestling was in this feud. The matches are all very solid, but man on man the wrestling is totally secondary to the characters involved, Dusty can throw 1 punch and have it give you chills, that's how good he was. Again, I don't need to spill anymore ink over this, if you know wrestling you know the biggest feud of the 80's was Flair vs Rhodes. Must watch for any wrestling fan.
7. Ricky Steamboat/Jay Youngblood vs Briscoe Brothers. As good as the Slautghter/Kernoodle feud, this matches right up with it, only instead of blood soaked brawls they worked technically perfect, psychology heavy tags that were every bit as exciting and enjoyable. The Briscoe's were just vile, evil people, it's amazing to watch how much heat they could get doing such simple things.
8. Ric Flair vs Terry Funk. My 2 favorite Flair matches of all time were with the Funker, here he was middle aged and crazy, bat shit crazy, and also probably the best heel in the history of wrestling. The Funker is in my opinion the best wrestler ever, while Flair is
#2 . That tells you all you need to know, when the best and 2nd best ever, in both of their primes, collided for a magical feud at the end of the 1980's.
Let me know if you need any more recs