I've tallied up the responses in this thread to this point. I know a poll would have been easier, but hey. I guess I'm old fashioned.
I understand that this thread is such a small sample size, and we will never truly know the real answer unless extensive research is done.
However, using the results of the DT League, the results of this thread, and any other outside info provided, we can at least come up with some good ballpark guesses as to what the most universally beloved DT song is by the fans.
Metropolis: 16
A Change Of Seasons: 6
Octavarium: 6
Learning To Live: 6
Take The Time: 4
The Spirit Carries On: 3
Breaking All Illusions: 2
Home: 2
The Glass Prison: 2
Lines In The Sand: 1
So based on this thread alone, we've got some good evidence to indicate that Metropolis MAY be the closest answer. Though, as Tootsie Pop would say, the world may never know.