Hysteria was a masterpiece of production, wedded to some solid songwriting that showcased a wider array of musicianship and performance than Def Leppard had shown before, and it was an unexpected resurgence from a group whose future had been in doubt since Allen’s accident and the 4-year hiatus after Pyromania (which had some excellent songwriting and more raw performances).
But to put it ahead of Appetite? Hardly. Better songwriting, better musicianship, and production that was more true to the soul of the band. In fact, Rolling Stone aside (and let’s face it, they never took 80s hard rock seriously) you’ve got serious competition for the best hair metal album from Dr Feelgood, Skid Row, and Slippery When Wet, all of which featured (a) exceptional songwriting, (b) outstanding production work (though it would be nice to get a remix of SR’s debut along the lines of their 2nd album), and (c) excellent musical performance for the songs.
Yeah, sure, someone is going to point out how such-and-such is a “better” guitarist than Mick Mars or Richie Sambora or Phil Collen, but those guys were all perfect for the music they were playing on those albums and the performances on those albums were ideal for what they were playing.
Now, here’s the mile-wide caveat: whither Metallica? If you count them in the same genre, then Master of Puppets jumps to #2 behind Appetite for Destruction, and the discussion continues from there.
The follow-up caveat is this: what about Ozzy? Because his Crazy Babies and No More Tears (with Zakk Wylde on guitar) were not the most commercially-successful of his solo records, but check all the key boxes above: songwriting, production, and performance.