GOAT feud was Stone Cold V. Vince McMahon. Next closest was Rock v. Stone Cold. Rebranded Crow Sting vs NWO had me stoked for a while, but like every feud involving the NWO (for me), the big payoff never materialized. The army of Stings taking on the NWO was amazing.
Old school, Superfly Jimmy Snuka v. the Magnificent One Don Muraco was awesome.
The return of the Superstar Billy Graham v. Backlund was fun. Graham was legit scary looking. Backlund looked genuinely shook when the Superstar ripped his belt apart.
Von Erichs vs. the Freebirds in World Class Championship Wrestling was an amazing feud with some great matches. I rewatched tapes of those matches for years.
Honorable mention to Andy Kaufman v. Jerry Lawler. I didn't see them on Mid-Southern, but I saw them on Letterman and even though I knew wrestling was fake, I 100% believed Lawler was assaulting him on national TV.
Also, was a big fan of Mankind(Mick Foley) vs. Undertaker. Foley was just crazy, but also funny goofy at same time.