I know this will make me a minority, but Train Of Thought is the only Dream Theater album that I can enjoy...I rediscovered it after reading this thread, and I have to say, it fucking owns! There are a few drawbacks:
1. Nearly every other vocalist going > James LaBrie
2. Some REALLY shitty keyboard sounds
3. Not very good lyrics
But the bulk of the songs is excellent, and it has this marvellous thick sound that I love. It's fiddly like DT is supposed to be....but not TOO fiddly.
Octavarium is not as bad as I thought it would be from the reviews, but then I've only heard about half of it. But then....the reviewers slaughtered it, so it would have been REALLY hard to be that bad. It's a poor follow up, in my opinion.