What do you feel is the greatest concept album of all time?

Personally, I need more time to think about this because there are so many that I adore...I'll get back to it when I have some time to kill...but feel free to post your selections...

Thinking about it only glancingly here's my top 3:

1. Quadrophenia - The Who
2. Arthur or the Rise and Fall of the British Empire - The Kinks
3. The Who Sell Out - The Who


I know I'm leaving out Sgt. Pepper, but I haven't yet explored Beatles music yet so I can't really comment on them.

I'll go with Tommy by The Who... While Sgt. Pepper is considered a concept album, I don't really classify it as such because it is so very loosly tied together...


-

Quadrophenia - The Who
Tommy - The Who
The Wall - Pink Floyd

Actually there are a number of Floyd albums that have a common theme running throughout the
album so I would add Animals, Dark Side of the moon, and the Final Cut, if you would call them concept albums.

I don't know if it's 'the greatest', but one that should definitely be checked out is by a group called the Rheostatics. The album is called "Songs Inspired by the Group of Seven" Beautiful album.

I'm not entirely sure on the definition of a concept album but I think Blur-13 is kind of conceptual. I love Abbey Road too.

Spacemen 3 - Perfect Prescription

It loosely follows a trip (or a hit, you never know with them) that goes from good to bad. And it's beautiful.

pink floyd - the wall
radiohead - the bends (im pretty sure this could be considered a concept album)
the beatles - sgt pepper

"Pet Sounds" by the Beach Boys (almost never considered in this category, but most definitely a concept album in every way, musically, lyrically, thematically--the first in rock...and perhaps the best).