In baseball, back to back to back homeruns are rare.  In music, I'd say it's even rarer.  What are some bands/solo artists that made THREE straight classic/epic albums IN A ROW?  If one of the albums is just "good" then it doesn't count.  Off the top of my head:

Bruce Springsteen

-The Wild, the Innocent and the E-Street Shuffle

-Born to Run

-Darkness on the Edge of Town

The Beatles

-Rubber Soul

-Revolver

-Sgt. Pepper's....

The Rolling Stones (4)

-Beggar's Banquet

-Let it Bleed

-Sticky Fingers

-Exile on Main Street

The Who(4)

-The Who Sell Out

-Tommy

-Who's Next

-Quadrophenia

Bob Dylan

-Bringing it all Back Home

-Highway 61 Revisited

-Blonde on Blonde

Radiohead

-The Bends

-OK Computer

-Kid A

Arcade Fire

-Funeral

-Neon Bible

-The Suburbs

Biggest upsets, to me, are REM (Automatic for the People isn't QUITE up to snuff) and Led Zeppelin (would have had 4 in a row, but "3" is just good, not great).

I'm sure there are others, but they escape me right now, I'll add as I go along.

Arcade Fire for me.

I'd say Zeppelin IV, Houses of the Holy, and Physical Graffiti are all great.

D'oh!

Arcade Fire easily makes the list, editing.

For Zeppelin, Houses of the Holy I just consider good not great.  The other two are great, to be sure.

With some slight cheating....

Tom Petty
- Full Moon Fever

- Into The Great Wide Open (with the Heartbreakers)

- Wildflowers

U2

- The Joshua Tree

- Rattle and Hum

- Achtung Baby

Maybe not there... Rattle and Hum not great, even though the other two are highly regarded.

Marshall Mathers
- The Slim Shady LP

- The Marshall Mathers LP
- The Eminem Show

Some other possibilities... Cream, Eric Clapton, Elton John, Van Morrison, David Bowie, Elton John, Roy Orbinson, Johnny Cash, The Clash, Muddy Waters, Beach Boys...

Awful lot of outstanding artists that haven't done 3 great albums in a row.

I'd say Zeppelin IV, Houses of the Holy, and Physical Graffiti are all great.

When I saw the OP, that was my thought. I consider HOTH a bit underrated, even though its caliber is recognized by many folks, and for some reason "The Rain Song" gets almost no airplay (just like "Achilles Last Stand" from Presence). There are occasions when I'll put HOTH on before Untitled. Guess it depends on the mood?

Just came across this thread.   I was ready to come in here and  throw out 3 stragiht from the Beastie Boys, but Check Your Head throws a wrench into the 3 peat,  It's either the weakest on the back end proceeded by Licensed To Ill and Paul's Boutique.  Or it's the weakest on the front end followed by Ill Communicaton and Hello Nasty.  But hey 4 out 5 ain't bad!

Just came across this thread.   I was ready to come in here and  throw out 3 stragiht from the Beastie Boys, but Check Your Head throws a wrench into the 3 peat,  It's either the weakest on the back end proceeded by Licensed To Ill and Paul's Boutique.  Or it's the weakest on the front end followed by Ill Communicaton and Hello Nasty.  But hey 4 out 5 ain't bad!

Beasties are very very close.  I agreed with you about Check Your Head.

I almost want to go back and put REM in there -- they're one of my top 3 bands of all time, but the problem, for me at least, is that every 2-3 albums is only "good" not "great" and it needs to be "great" to be mentioned here.  Hmmmm, maybe "Document" "Green" and "Out of Time".

I also forgot the Hold Steady:  Separation Sunday, Boys and Girls in America and Stay Positive.

Arcade Fire's next album looks to be amazing, and they will join the few elite with 4 in a row.

Arcade Fire and Radiohead for sure. Good call.

Off the top of my head...

Pearl Jam: Ten, VS, Vitalogy.

Beastie Boys: License to Ill, Paul's Boutique and Check Your Head, Ill Communication

The National: Alligator, Boxer, High Violet

The Strokes would have been fast-tracked on this list but First Impressions was a step down from their first two albums, although still pretty good.

Brand New: Your Favorite Weapon, Deja Entendu...... ahh... well, I guess back-to-back ain't bad, eh? 

Rage Against the Machine:  Rage Against the Machine, Evil Empire, The Battle of Los Angeles