1. Nine Inch Nails - the downward spiral
2. Nirvana - Unplugged in NY
3. Radiohead - The Bends
4. Garbage - Version 2.0
5. Rage Against the Machine - s/t
Ask again in a week and it may be different.
EDIT: Gotta add some honorable mentions ...
Cake - Fashion Nugget, Prolonging the Magic
The Doors - Morrison Hotel
Bob Dylan - Bringing it All Back Home
Eminem - Slim Shady LP, Marshall Mathers LP
Fight Club - score
Foo Fighters - The Colour and the Shape
Incubus - S.C.I.E.N.C.E.
Led Zeppelin - II, III, IV
Method Man & Redman - Blackout!
Nine Inch Nails - Pretty Hate Machine, Broken, The Fragile
Nirvana - Nevermind, In Utero
Offspring - Smash
Outkast - Big Boi and Dre Present ...
Pearl Jam - Ten, Vs., Vitology
A Perfect Circle - Mer de Noms
Pink Floyd - Dark Side of the Moon, Wish You Were Here, The Wall
Pixies - Doolittle, Surfer Rosa
Radiohead - OK Computer, Kid A, Amnesiac
Smashing Pumpkins - Siamese Dream
Soundgarden - A Sides
The Streets - Original Pirate Material, a grand don't come for free
Sublime - Greatest Hits
System of a Down - s/t, Toxicity
Tenacious D - s/t
Tool - Ænima, Lateralus
Weezer - s/t (blue), Pinkerton
The White Stripes - De Stijl, White Blood Cells, Elephant
Wu-Tang Clan - 36 Chambers
Yeah Yeah Yeahs - Fever to Tell