Most played cards in Millstone Dreams:

4 Decks
Disenchant
16 copies - 4 average
Counterspell
16 copies - 4 average
Tundra
16 copies - 4 average
Swords to Plowshares
15 copies - 3.75 average
Millstone
14 copies - 3.5 average
City of Brass
14 copies - 3.5 average
Serra Angel
11 copies - 2.75 average
Copy Artifact
11 copies - 2.75 average
Field of Dreams
10 copies - 2.5 average
Mishra's Factory
9 copies - 2.25 average
Dust to Dust
6 copies - 1.5 average
Maze of Ith
6 copies - 1.5 average
Moat
6 copies - 1.5 average
Ivory Tower
5 copies - 1.25 average
The Abyss
5 copies - 1.25 average
Circle of Protection: Red
5 copies - 1.25 average
Mox Sapphire
4 copies - 1 average
Blue Elemental Blast
4 copies - 1 average
Serendib Efreet
4 copies - 1 average
Strip Mine
4 copies - 1 average