Most played cards in Mill:

5 Decks
Brainstorm
20 copies - 4 average
Archive Trap
20 copies - 4 average
Ruin Crab
20 copies - 4 average
Force of Will
20 copies - 4 average
Glimpse the Unthinkable
20 copies - 4 average
Leyline of the Void
20 copies - 4 average
Surgical Extraction
20 copies - 4 average
Hedron Crab
20 copies - 4 average
Daze
20 copies - 4 average
Scalding Tarn
20 copies - 4 average
Polluted Delta
20 copies - 4 average
Ponder
15 copies - 3 average
Mission Briefing
15 copies - 3 average
Visions of Beyond
15 copies - 3 average
Grafdigger's Cage
10 copies - 2 average
Volcanic Island
10 copies - 2 average
Thoughtseize
10 copies - 2 average
Underground Sea
10 copies - 2 average
Flusterstorm
10 copies - 2 average
Ashiok, Dream Render
10 copies - 2 average