Led Zeppelin – IV
Aerosmith – Toys in the Attic
Butthole Surfers – Hairway to Steven
Beatles – White Album
backing up others, here, on Bowie’s “Ziggy…”
Velvet Underground – Loaded
The Jesus Lizard – Liar
Rolling Stones – gotta be a tie between Beggar’s Banquet and Let it Bleed.
Nile – In Their Darkened Shrines
AxCx – Everyone Should Be Killed
agree with Blondebear’s The Who – Who’s Next/Live at Leeds
Big Black – Songs About Fucking
Neil Young – gotta be (I think an obvious?) tie with After the Gold Rush and Harvest
agree with scuirophobic’s Blondie – Parallel Lines
King Crimson – ugh – if I had to choose between “Lark’s Tongues in Aspic”, “Starless and Bible Black” and “Red” – I’d go with – ah, hell, I’ll go with all three.
Black Sabbath – Vol. 4
The Fall - Nation’s Saving Grace (but others - SO CLOSE)
Gang of Four – Entertainment
Steely Dan - Can’t Buy a Thrill
Rush - tie again – Farewell to Kings and Permanent Waves
agree with QQ Switcheroo – Billy Joel – The Stranger (by a gigantic longshot)
Jimi Hendrix - Cry of Love
Not Available, of course.
I’d have to go with Locust Abortion Technician From “Sweat Loaf” to both “Graveyards” to “22 Going on 23”. Just a masterpiece.
“Warning! Not as good as Atomizer, so don’t get your hopes up, cheese!” - Big Black
(Yeah, that sticker actually appeared on Headache. Too good to pass up!)
Well, I’d pick Rust Never Sleeps. “Hey Hey, My My (Into the Black)” and “Powderfinger” are my favorite songs of his.
I’m going to add Meatloaf - Bat Out of Hell here. Every song on that album is a powerhouse and he (and Jim Steinman) never came remotely close to those heights again, even when they recorded the “sequel.”
Yeah, another goodie, but no love for my favourite off that one - “The O-Men”? 
EDIT: Discordance Axis - The Inalienable Dreamless (oh my goodness)
Yep, every track off of it is beautiful. 
“USSA”, “Hay”, gimme them all!
Sonic Youth - Daydream Nation
ETA: The Cramps - Songs the Lord Taught Us
Bit of a cheat but…
Sex Pistols - Anarchy in the UK
will also suggest:
Dire Straits - Making Movies
Eagles - Hotel California
Hootie and the Blowfish - Cracked Rear View
Wilco - Yankee Hotel Foxtrot
Agree that Beatles, Stones, Springsteen, Dylan, REM and Petty have such extensive and varied catalogs that choosing just as their best is completely subjective.
Ten Years After/ A Space In Time
Deep Purple / Machine Head
And “All The World’s A Stage” by Rush.
I also nominate:
Murmur - R.E.M.
Fun? - The Candy Skins
Fountains - Starcastle
(the above two bands have never heard of you, either)
Forever Changes - Love
War - U2
Boston - s/t
Jane Siberry - s/t
Meatloaf Bat out of Hell
Concrete Blonde Bloodletting
Cyndi Lauper She’s So Unusual
Beach Boys Pet Sounds
Talking Heads Stop Making Sense
Jane’s Addiction Nothing’s Shocking
Kansas - Leftoverture?
It could be Point of Know Return but I think Leftoverture is the outstanding, stand-out album.
This was the problem that kept me from coming up with a good answer for Genesis.
Agreed! Good album but I’ll still take the first four.
Pure GOLD! Saw him play at U of Idaho on his 100% Fun tour. I’m sad to know about his health issues and hope he can someday recover.
My contribution: The Strokes - First Impressions of Earth. I’m a huge Strokes fan, but love this one the most. I know most people would list Is this It.
BTW, they are the musical host on SNL tomorrow.
“Weird Al” Yankovic - Dare to be Stupid
The Call - Let The Day Begin
The Swirling Eddies - Zoom Daddy
Leonard Nimoy - Two Sides of Leonard Nimoy
While I agree that ‘August and Everything After’ is a perfect album and one of my favorites, I submit that ‘Butter Miracle’ and ‘Somewhere Under Wonderland’ are better and much more fun to listen to.
What if I told you I used to have a Turbo C/C++ programming guide written by Herb Schildt?
Other albums had more of the radio hits but I think this one is better as a cohesive whole. Each song fits in perfectly with each other.
Someone above answered incorrectly for Steely Dan. It’s The Royal Scam.
No mention of Joni Mitchell’s ‘Blue’ yet? Amazing!
Los Lobos: How Will the Wolf Survive?
“Electric Ladyland” by the Jimi Hendrix Experience. Not just for “All Along the Watchtower” and “Voodoo Child (Slight Return)”, which are still played on Classic Rock radio stations 58 years later. The long, bluesy version of “Voodoo Chile” still makes my heart speed up a few beats per minute. With Jimi as Producer, it’s one of the iconic Rock albums of all time. And the list of backing musicians is a virtual who’s-who of rock & roll royalty of the time period.
There’s just something about sophomore albums…
Nevermind - Nirvana
Doolittle - The Pixies
Wild Gift - X
The Freewheelin’ Bob Dylan - Bob Dylan
This Year’s Model - Elvis Costello
Dawn of the Dickies - The Dickies