This, actually, would be an interesting topic for discussion.

What albums can you think of that work best as a single unit? An album where you can't imagine just one song being played?

Note: The following things are excluded from this discussion because they are "given": Most Pink Floyd albums, most live concert albums, and any symphonies or rock operas. I'm talking about albums that are merely a collection of songs, but they have some magical, subtle connection between the songs that makes the whole album pull together as a cohesive unit.

I can think of very few. One of the items on this following list surprised me, but every time one of its songs comes up, I have an irresistable urge to unshuffle:

Rush: Moving Pictures
Rush: Power Windows
Rush: Permanent Waves
Queen: A Night at the Opera
They Might Be Giants: Mink Car
Peter Gabriel: So
Dire Straits: Brothers in Arms
Sting: The Soul Cages (this one borderlines on non-inclusion, it is almost an opera)
The Police: Synchronicity
U2: The Joshua Tree

Most of mine are in the neighborhood of the Progressive Rock genre because that's what I listen to the most. I'm interested in hearing other's opinions from other genres. For instance, I'm told that Elton John's "Tumbleweed Connection" fits perfectly into this discussion, however I don't own that album so I don't know about it.

And it's not just because these albums are personal favorites, or because I like all of the songs on the album. Going through my artist list, there are many on the list which I listen to frequently and are top favorites, but which do not hang together well as an album. For example, one of my all time favorite albums is Tori Amos' "Little Earthquakes". But I don't see it as anything more than the sum of its parts. It is a collection of absolutely incredible songs, every single one of them, but there's nothing special about their inclusion onto the same album. They don't flow into a single uninterruptible experience the way the others do.