A few more suggestions, amongst my favorites. Not all "masterpieces", but all stellar efforts:
Pixies:
Surfer Rosa
Doolittle
Bossanova
Trompe Le Monde
PJ Harvey:
Dry
Rid of Me
To Bring You My Love
Is This Desire?
Stories From the City, Stories from the Sea
Flaming Lips:
Transmissions from the Satellite Heart
Clouds Taste Metallic
The Soft Bulletin
Yoshimi Battles the Pink Robots
Built to Spill:
There's Nothing Wrong with Love
Perfect From Now On
Keep It Like a Secret
Ancient Melodies of the Future
Guided By Voices:
Bee Thousand
Alien Lanes
Under the Bushes, Under the Stars
Mag Earwhig
Pavement:
Slanted and Enchanted
Crooked Rain, Crooked Rain
Wowee Zowee
Brighten the Corners
Pixies:
Surfer Rosa
Doolittle
Bossanova
Trompe Le Monde
PJ Harvey:
Dry
Rid of Me
To Bring You My Love
Is This Desire?
Stories From the City, Stories from the Sea
Flaming Lips:
Transmissions from the Satellite Heart
Clouds Taste Metallic
The Soft Bulletin
Yoshimi Battles the Pink Robots
Built to Spill:
There's Nothing Wrong with Love
Perfect From Now On
Keep It Like a Secret
Ancient Melodies of the Future
Guided By Voices:
Bee Thousand
Alien Lanes
Under the Bushes, Under the Stars
Mag Earwhig
Pavement:
Slanted and Enchanted
Crooked Rain, Crooked Rain
Wowee Zowee
Brighten the Corners