"Epic" compositions worth giving a spin

Personal favorites listed below, some already mentioned. You can add to this list any one of 100s of symphonies and tone poems but the likes of Bruckner, Dvorak, Strauss, Mahler, Sibelius, Elgar, Shostakovich, etc....the list goes on and on.

Camel: Snow Goose….
ELP: Pictures at an Exhibition, Tarkus and Karn Evil 9
Pink Floyd: Dogs, Echoes, The Wall, Atom Heart Mother Suite
Jethro Tull: Thick as a Brick
RUSH: 2112, Cygnus X-1 Book I: The Voyage and Book II: Hemispheres,
RUSH: La Villa Strangiato, The Fountain of Lamneth, Xanadu
Genesis: In This Cage->Afterglow, Supper’s Ready
Genesis: Cinema Show, The Battle of Epping Forest
Queensryche: OPERATION MINDCRIME
YES: Gates of Delirium, The Revealing Science of God, Close to the Edge:
Dream Theater: Six Degrees of Inner Turbulence, Change of Season, Octavarium
Dream Theater: In the Presence of Enemies, Metropolis Pt. 2
Supertramp: Fool’s Overture
Spock’s Beard: The Great Nothing, The Water
Green Carnation: Light of Day/Day of Nothing
Keith Jarrett: The Vienna Concert, The Kohn Concert, etc…
master of long improvisations on themes spanning entire concerts
Pat Metheny Group: The Way Up:
SOLARIS: Marsbéli Krónikák (Martian Chronicles)
SOLARIS: Nostradamus: Próféciák könyve (Nostradamus: Book of Prophecies)

Forgot to include the following;

ELOY: Land of No Body, The Light from Deep Darkness, Poseidon's Creation, 
"Atlantis' Agony at June 5th - 8498, 13 p.m. Gregorian Earthtime", The Apocalypse,
Reflections from Spheres Beyond, The Answer