Jimi Hendrix - "Electric Ladyland"
Pink Floyd - "Dark Side of the Moon", "Wish You Were Here", "Animals", "The Wall"

Metallica "Master of Puppets"..

Sexpistols-Never Mind The Bullocks, Here's The Sexpistols
Misfits-Famous Monsters
Slipknot-Slipknot
System of a Down-Toxicity

Bad religion-new maps of hell

The offspring-smash

Boards Of Canada- Music Has the Right to Children

Radiohead-Ok Computer.

Midlake-Trials Of Van Occupanther

Meat Puppets-Up On The Sun

Rem-Fables of the Reconstruction

Replacements-Let it Be

Glen Campbell-Meet Glen Campbell

Autechre-Incunabula

Neko Case- Blacklisted, and Fox Confessor Brings the Flood

U2-Boy, October, Under a Blood Red Sky, Unforgettable Fire, Joshua Tree, And Achtung Baby.

Tool-undertow, and Laterlus.

To name a few.

Pearl Jam - Ten
Flaming Lips - Yoshimi Battles the Pink Robots
The Shins - Chutes Too Narrow
Counting Crows - August and Everything After
NWA - Straight Outta Compton
Dave Matthews Band - Under The Table and Dreaming; Before These Crowded Streets
Widespread Panic - Till The Meidcine Takes
The Thrills - So Much For The City
Radiohead - OK Computer

Southern Rock Opera by the DBT

Black Love by the Afghan Whigs

Deltron 3030 - Deltron 3030
Pancea - The Scenic Route
The Hush Sound - Like Vines
The Format - Dog Problems
Emery - The Weak's End
Camille - Le Fil
Bloc Party - Silent Alarm
Bloc Party - A Weekend In The City
The Postal Service - Give Up
Zero 7 - The Simple Things
Ludo - Broken Bride

For those of you who have never listened to Ludo, please check out Broken Bride. 5 song epic rock opera which is definitely one of the best album's I have ever heard.

Off the top of my head, in no particular order:

Pink Floyd- Division Bell, Dark Side
Metallica- ...And Justice For All
Sublime- 40oz To Freedom
Pearl Jam- Ten
The Police - Synchronicity
Rush- Moving Pictures, 2112
Dr. Dre- The Chronic

Funeral For A Friend - Hours
Fatboy Slim - You've Come A Long Way, Baby
Justice - Cross
Mogwai - Happy Songs For Happy People
Portishead - Third
Air - Moon Safari
Slick Rick - The Great Adventures of Slick Rick
The National - Boxer
The Album Leaf - Into The Blue Again

lately:
Girls Against Boys - You Can't Fight What You Can't See
Russian Red - I Love Your Glasses