The best era of music ever is the very late 60s to the mid 70s. If you add soul and folk to the equation, the decade is basically untouchable.
Jimi Hendrix- Are you Experienced?, Axis: Bold as Love, Electric Ladyland
Led Zeppelin- I, IV, Houses of the Holy, Physical Graffiti (specifically disc 1)
King Crimson- In the Court of the Crimson King, Islands, Larks Toungues in Aspic, Starless and Bible Black, Red
Jethro Tull- Aqualung, Thick as a Brick
Rush- Caress of Steel, 2112, Farewell to Kings, Hemespheres
Pink Floyd- Darkside of the Moon, Wish You Were Here, Animals
Yes- Close to the Edge
Bob Dylan- Highway 61 Revisited, Blonde on Blonde
Van Der Graaf Generator- Pawn Hearts
Joy Division- Unknown Pleasures
The Doors- Self-titled, Strange Days, Waiting for the Sun
Black Sabbath- Paranoid, Masters of Reality, Sabbath Bloody Sabbath, Sabotage
Judas Priest- Sad Wings of Destiny, Sin After Sin, Stained Class