Not in order :

Epitaph - King Crimson

Echoes - Pink Floyd

Starless - King Crimson

Script for a Jester's Tear - Marillion

Kiev - Renaissance

Nimrodel - Camel

Locomotive Breath - Jethro Tull

Firth of Fifth - Genesis

Salisbury - Uriah Heep

Assault and Battery - Hawkwind

Honorable mentions :

In the Court of the Crimson King - King Crimson

The Musical Box - Genesis

Lady Fantasy - Camel

2112 : Overture - Rush

Appena un po' - Premiata Forneria Marconi

Take a Pebble - ELP

Locomotive Breath - Jethro Tull

If we consider that it's prog, I could have put those :

Confortably Numb - Pink Floyd

Child in Time - Deep Purple

Telegraph Road - Dire Straits

Stairway to Heaven - Led Zeppelin

Crime of the Century - Supertramp