The 80's hands down. I watched a lot of wrestling in the 90's and spent most of the decade bored to death, largely because of the 1980's.
First, it was in the 80's that wrestling expanded from local, regional based TV and arena shows into a major international promotion. Watching that change take place was literally for a wrestling fan like watching major sports history.
The biggest names in wrestling history came from the 80's. Brett Hart had a nice run in the 90's but he never reached the heights Flair, Hogan, Savage, or Piper did. Dusty Rhodes is in there too although he was big in the 70's (much like Hogan was still big in the 90's).
The "Monday Night Wars" that everyone talks about was nothing like the Jim Crockett/Vince McMahon war in the 80's. As McMahon expanded nationally (stealing top talent from local promotions along the way) Crockett matched him almost step for step for much of the decade. The television and events produced were some of the best in any era of wrestling (and better than almost anything from 1990-97).
You also had two distinctly different products in competition. The NWA produced edgier, more adult oriented content with better matches while WWF
produced "entertainment spectacles" complete with rock concert pyrotechnics and high tech visuals with true larger than life characters.
Hulkamania was bigger as a national phenomenon than anything in the 90's, bigger than "Attitude" , the NWO, the "Monday Night Wars", Hogan, as the public face of the WWF helped move the company (and the wrestling industry as a whole) into an entirely different business model, the model of international promotion that continues today. Ric Flair set the absolut standard for top level wrestlers, combining character, in ring ability, and mic skills better than anyone before him. He not only thrived in the more "entertainment oriented" scheme of the 80's but his influence is still felt today. Certainly anyone who has watched Chris Jericho, Shawn Michaels, or HHH from 97-2007 knows Ric Flair was one of (if not the biggest influence).
For most of the 90's until the end wrestling in general was in a creative rut, WWF was boring and repetitious with only a handfull of memorable stars or feuds and very few "Superstars" being created. From 1990-1996 how many "Superstars" came from either WWF or WCW ? Most of the biggest names in the industry were either stars who first became top level in the 80's (Flair, Hogan, Savage, Sting, Luger, Henning, Hall, Rick Rude, Hart, Michaels) or they were short term mid card talent elevated briefly due to a lack of star power.
Furthermore, so much of the "Attitude" era looked like 80's NWA re-do, updated for a new decade. While McMahon promoted "family entertainment" in the 80's, the NWA gave us parking lot beat downs with baseball bats, attempted lynchings (Dusty Rhodes & Magnum TA tying rope around Jim Cornette's neck and attempting to drag him behind Dusty's pick up), manequins dressed like female valets being stripped and molested during interviews, and significant (for the time) violence perpetrated by men against women, not to mentio brutal steel cage matches, the forerunner to the late 90's Hell In A Cell that were far more viscious than anyhing seen for most of the 90's.
The 1980's saw the creation of PPV events as well, another cornerstone of the business model that exists today.
As for matches, most of 1990-1996 is a boring blur for me except the occassional Hart/Michaels or Sting/Flair match. For most of the 80's other promotions were still around so if you were bored with Hulkamania or not interested in the exploits of The Four Horsemen you could still watch the AWA and see Shawn Micheals winning tag team championships or the phenomenal Curt Henning/Nick Bockwinkle matches. The UWF, with it's accent towards more blood, brawling style was an insurgent force against the superpowers of McMahon and Crockett, much like ECW was against McMahon and Bischoff. In the 90's you basically had only two options, one of which was boring and repetive and the other woefully mismanaged and hard to watch.
From start to finish the 80's was "The Decade" in pro wrestling. Not only laying the groundwork for many of the stories in the 90's but creating almost all of the 90's top stars and defining the basic framework of the business as a whole that exists today. The 90's had probaby three really good years from 96-early 99 when it was really fun to watch. Prior to that it was just a ho hum product surviving mostly on the strength of the prior decade's biggest names.