1990s eh?
Albums are easier for me:
Depeche Mode - Violator
Eric's Trip - Love Tara
Radiohead - Duh
Sonic Youth - Washing Machine
Stereolab - 2 great albums in the 90s
Tom Waits belongs on any list
Tool - Undertow and Aenima
Rage against the Machine - 2 fantastic albums in the 90s
Red Hot Chili Peppers - Blood Sugar Sex Magik
Santana - Supernatural
Guns 'n Roses - Use your Illusions
Massive Attack - Blue Lines and Mezzanine were both good; Tricky's Pre-Millennium Tension also filed here
Ministry - Psalm 69
REM - Automatic for the People
Tragically Hip - Day for Night
PJ Harvey - Rid of Me and To Bring You My Love
NaS - as previously mentioned
Sarah McLachlan - Solace and Fumbling Toward Ecstacy
Sinead O'Connor - I do not want...
Eric B and Rakim - Let the Rhythm Hit 'Em and Don't Sweat the Technique
NIN - The Downward Spiral
Public Enemy - Fear of a Black Planet
Portishead - both Dummy and their eponymous album were amazing
Primus - Tales from the Punchbowl