Unpopular opinion : Best Dream Theater album.
The album depth is huge, the main topic being "how can you be original, knowing that we all work with the same matter ?". Dream Theater here explores various styles, and the structure itself is made as an octave interval.
The "Octavarium" track was a revelation for me, especially the divinly wizzardy keyboard solo of Jordan Rudess (the goat). Yeah I'm a keybooardist, how could you tell ?

Well, it is both a sensorial experience and intellectually reflexion leading me on new perspectives !