Images & Words - Truely a masterpiece of metal/rock. Completely original with tracks that both stand on their own and flow together. Love the reoccuring themes of light/dreams/day/night/sleep.
Awake - Amazing album, all the songs are killer. In my opinion it's not as cohesive as Images & Words, and (I know I'm in the minority in saying this), excessive use of JLB's vocal range.
Scenes From a Memory - This album saved the band from the disaster that was FII. Classic, influential prog album that has been intimidated by many bands. A couple songs drag on a bit and Through Her Eyes sounds terribly dated.
Train of Thought - Vastly underrated by the fans. It's amazing they wrote this album as quickly as they did. Every song is quality, and Mike Portnoy is just on fire for the whole album. Some of the songs suffer from overlength, however.
A Dramatic Turn of Events - One of DT's most consistent album. Also contains their two best "ballads" with Beneath the Surface and Far from Heaven. Suffers from poor production and a couple dud songs including one of their worst, Build Me Up.
Six Degrees of Inner Turbulence - Great album, interesting concept. My only gripe is that it suffers from a slightly high cheese factor - even for DT.
Octavarium - Contains some of DT's best songs. Unfortunately, there is definite filler here, and some awful, cheesefest songs.
DT12 - Overall a consistent album, it feels a bit derivative though. DT has never been about keeping with the times but this album has an overall archaic, dare I say washed up feel. The members have expressed that this was meant to be a statement about the band, unfortunately it seems like they didn't have much to say.
Black Clouds & Silver Linings and Systematic Chaos (tie) - Not bad albums, but to me they were both steps backwards for DT. This to me is when the band started playing it safe, focusing more on sounding like other bands, and create paint by numbers DT songs. That said, Count of Tuscany and Nightmare to Remember are classic.
When Dream & Day Unite - I can't judge this album very harshly, some of these songs were written when DT were teenagers. A great preview of things to come but doesn't really hold up on it's own.
Falling Into Infinity - Worst they've done, by a long shot. Production is bad, songs are forgettable, cheesy, derivative. I'm surprised DT actually survived this album. And, no, Hollow Years is not a good song.