As terrible as the mainstream got in the 90's (real dark ages for sure), there was an incredible amount of quality music released just as well. No shortage of great albums to pick from so I gotta go with the classics here.
Danzig - Danzig III: How the Gods Kill
"I'm gonna stand, at the top of the world, challenge the heavens, gonna bring you god"
For whatever reason Danzig III isn't the most memorable Danzig record for me. I find myself overlooking it quite a bit and I really shouldn't because it is a terrific album. Coming off the heels of Danzig II, the album has some mighty big shoes to fill. The approach here is slightly more straightforward with power chord driven rockers dominating the tracklist. Even so, Danzig III includes two of Danzig's best (power) ballads - "How The Gods Kill" and "Sistinas". Good stuff and nothing but.
Megadeth - Countdown To Extinction
Here's another no brainer. There are 3 albums in the Megadeth discography that are easy recommendations for novices - Peace Sells for the 80's metal/thrash fan, Rust In Piece for anyone into the more technical/progressive style and Countdown To Extinction for pretty much anyone else (I guess you could also recommend Youthanasia for grunge fans). The perfect balance of heavier cuts and more approachable material with plenty of hooks and catchy choruses thrown in the mix. "Something for everyone" doesn't always work this well. It's hard to deny that CTE is and will likely remain the pinnacle of Megadeth's career in the eyes of the general public.
Pantera - Vulgar Display of Power
The quintessential Pantera record. Everyone has their favorites but this is where the band truly found their sound and is their most cohesive effort. A good chunk of classic songs and the rest are not far off. No fat on this one. Pure aggression with a few somber moments thrown in. Phil is still showcasing his singing chops here without relying on extremes too much. Favorites? "Mouth for War", "Walk", "Hollow"
Rollins Band - The End of Silence
And yet another career-defining record for 1992. I guess you could make the same case for it's follow-up (Weight) but without the excellence of The End Of Silence there wouldn't have been much to build on. Henry & co. offer the world a dose of high intensity tough love. Atleast that's what I take away from it. Like they're saying "This is how it is, now do something about it and prove us wrong". A lot of these songs are highly motivational. If you feel down and stuck in a hole, pay attention to the lyrics in a song like "Low Self Opinion" and pick yourself up. The world keeps turning with or without you.
Tom Waits - Bone Machine
Bone Machine can be considered the first of the modern Tom Waits albums. After a recording break of 5 years, Waits returned with a new sound much more experimental than ever before. Excellently crafted, there is enough variation between songs to keep the overall nature of the album from becoming too overbearing. Many of the songs have been featured on movie soundtracks (Twelve Monkeys, Fight Club) and covered by bands from the Ramones to Queens Of The Stone Age. To pick any single songs off here would only do a disservice to the album. If you're going to check it out, just listen to the whole thing. Tom would continue down this road on his future albums but so far Bone Machine is yet to be beat.