I'm looking for some that haven't been mentioned yet... Death Cab's Transatlanticism is unified by the theme of long-distance relationships, so if you consider that a concept album, that one isn't bad... The Crane Wife by The Decemberists is solid as well... I think someone mentioned In Absentia already, but Porcupine Tree is consistently amazing, Deadwing is great too... hmm you guys touched on a lot of great ones, Floyd, TMV...

When Phantom on the Horizon is finally released...it will tear all prior concept albums apart.