Here's a typically prog-lovers/epic-lovers list...(and in no real order, because that would take a lot of time to figure out...)
A Change Of Seasons
Six Degrees Of Inner Turbulence
Octavarium
The Count Of Tuscany
Illumination Theory
In The Presence Of Enemies
In The Name Of God
Trial Of Tears
Home
Learning To Live
Yeah, I love the long songs. I blame my love for bands like Yes, The Flower Kings and Spock's Beard/Neal Morse for that, but for me, DT's longer tracks/epics are some of their best pieces, with some amazing performances from the whole band.
-Marc.