First of all, I guess it's important to check out what was one of the biggest sounds of the time: grunge. The main groups of this movement were Soundgarden, Nirvana, Alice In Chains, Pearl Jam, and Stone Temple Pilots. Of those, I personally think Soundgarden was the best, and since you seem to like harder stuff, I'd highly recommend the albums "Badmotorfinger" or "Superunknown". Pearl Jam's "Ten" is also a great album. I can't speak for the other groups, though, as I'm not really a big fan of them.
What really made the 90s great, though, was the explosion of excellent indie rock and alternative bands. The most influential of the 90s alt-rock bands was probably Pavement. They made 5 superb albums; the best one to start out with is "Crooked Rain, Crooked Rain". Keep in mind that it takes a couple listens to grow because it really isn't a hugely accessible album. Some other important indie rock bands in the same vein are Built To Spill (check out "Perfect From Now On" or "There's Nothing Wrong Wth Love") and Flaming Lips (many say "Soft Bulletin" is their best, and it's their most accessible, but I think "In A Priest Driven Ambulance" and "Clouds Taste Metallic" far superior).
On the poppier side of 90's indie, there's stuff like Belle & Sebastian's "If You're Feeling Sinister" which is considered one of the best albums of the time, though again, it may be too poppy for you. Another well-regarded, and probably universally loved album is Neutral Milk Hotel's "In An Aeroplane Over The Sea", which is a great folk rock album that defies description, really. Apples In Stereo are a very Beatles/Kinks sounding band, check out "Tone Soul Evolution" from them.
Another album that's considered really important to alt-rock is "Loveless" by My Bloody Valentine; though I really could never get into it, I feel it's worth mentioning.
Getting back to more mainstream stuff, some of the biggest great bands of the 90s were the Red Hot Chili Peppers, Nine Inch Nails, Beck, Beastie Boys, Weezer, Radiohead, Ben Folds Five, Rage Against The Machine, Cake, Oasis, and Smashing Pumpkins:
Red Hot Chili Peppers were a funk rock band with hints of pop in the first half of the 90s, then a pop rock band with hints of funk in the second half. You probably know them, but check out "Blood Sugar Sex Magik" (for more funk) or "Californication" (for more pop)
Nine Inch Nails broke industrial rock into the mainstream. From what you said, it sounds like you like harder stuff, so you'd probably like them. Their best album, bar none, is "Downward Spiral", which is sort of a hard rock album with some electronica thrown in. "Broken" is also an excellent hard rock album.
Beck, who you probably know for the song "Loser" is an excellent genre-hopper in the vein of David Bowie. His album "Odelay" is a masterpiece; a combination of hip hop, rock, pop, folk, and numerous other styles. It's one of my top 10 albums of all time, and it's highly recommended. Also worth hearing is his 1999 album "Midnite Vultures" which was a homage to Prince music, and probably one of the most fun albums ever made.
The Beastie Boys may have had some of their biggest hits in the 80s, but they made most of their best music in the 90s. "Check Your Head" is an excellent example of rap-rock done right, and it manages to squeeze quite a few other genres into it. With some punk rock tracks, some jazzy instrumentals, and some great straight-up hip hop, it's almost their best album. (And I have to mention "Paul's Boutique" which was released 5 months before the 90s, but was hugely influential and proved that sampling is an artform).
Weezer made two perfect albums in the 90s in the form of The Blue album and Pinkerton. Both are alt-rock classics, and have tons of memorable melodies and hooks.
Radiohead are probably best known for being incredibly pretentious, but they certainly deserve all the praise they get for "OK Computer" and "The Bends". Both are rock masterpieces, though the vocals may take some getting used to. (If you like Muse, you'll probably like them though). I'd highly recommend listening to both, as usually people like one but not the other at first; they are also growers.
Ben Folds Five are a piano rock band best known for the song "Brick" which actually is nothing like the rest of their music. Both "Ben Folds Five" and "Whatever And Ever Amen" are great pop rock albums.
Rage Against The Machine is probably responsible for more terrible bands than any other band of the 90s, as they made rap-metal huge, but their self-titled album is excellent. With hard-hitting riffs, and charged vocals, it's a great album to rock out to.
Cake are sort of known as a novelty band for their hits like "The Distance" and "Short Skirt/Long Jacket" but they made several very solid albums of horn-boosted alt-rock, the best of which is probably "Fashion Nugget".
You probably know Oasis for "Wonderwall"; they're another Beatles-y alt-rock band. "(What's The Story) Morning Glory" and "Definitely Maybe" are two landmark rock albums that are strong from start to finish.
Finally, Smashing Pumpkins are a harder alt rock band that are sort of linked to the grunge scene but not really. They're very talented (just listen to those solos on "Siamese Dream") and have some very memorable hard and soft tracks on their albums (especially on "Mellon Collie and The Infinite Sadness")
Also, I can't get through talking about the 90s without mentioning Ween, who are my favorite band. Their music spans a wide variety of genres, and is often jokey in tone, but rarely musically. They are incredibly talented, and they made what is probably my favorite album of all time: "The Mollusk". It's a homage to/send-up of classic prog, and though it has songs like "Waving My Dick In The Wind" it doesn't feel like a joke. Each song is in a different style, but it flows together excellently as an album, and it has some of the most epic songs every written (seriously, check out "The Golden Eel" and "Buckingham Green")
I'm not that well-versed in metal of the 90s, so I'll let someone else take that one, but I would highly recommend Megadeth's "Rust In Peace" and "Countdown To Extinction".
Finally, I feel the need to point out that hip-hop was at it's best in the 90s. Ice Cube, Dr. Dre, Hieroglyphics, Wu-Tang Clan (and associates), A Tribe Called Quest, 2Pac, Outkast, The Roots, Nas, Public Enemy, Souls Of Mischief, Snoop Dogg, Digital Underground, and Del Tha Funkee Homosapien are all worth checking out. However, I know many probably have some predisposition to hating rap as a genre, so here are the albums that I would recommend to change the mind of a rap hater:
Public Enemy - Fear Of A Black Planet
A Tribe Called Quest - The Low End Theory
Wu-Tang Clan - Enter The Wu-Tang
Dr. Dre - The Chronic
Ice Cube - Death Certificate
Outkast - Aquemini
If you hate those, I don't know what to say.
(Wow, I didn't mean to write this much. Congratulations if you actually got this far. I hope it was helpful)
Of Montreal, Prince, Ween, & Pavement for DLC
Would you pay for music by Beck?
What if you heard he owned a plane made of gold?
Good, because he needs the money.
Corrosion of Conformity;
Passion and Warfare
Five Man Acoustical Jam
Space Age Bachelor Pad Music
To name a couple.
Originally Posted by Der_Lex
No, it's not ok to basically troll a thread like this. He can go be a jerk somewhere else for a while.
nice to see everyone's been hitting this thread hard.
also check out ildjarn...
while i personally prefer "forest poetry", i believe you'll find "strength and anger" to be just what you're looking for.