Most played cards in Parfait Oath:

2 Decks
Enlightened Tutor
8 copies - 4 average
Scroll Rack
8 copies - 4 average
Land Tax
8 copies - 4 average
Swords to Plowshares
8 copies - 4 average
Mox Diamond
8 copies - 4 average
Undiscovered Paradise
8 copies - 4 average
Meddling Mage
6 copies - 3 average
Windswept Heath
6 copies - 3 average
Oath of Druids
6 copies - 3 average
Gaea's Blessing
5 copies - 2.5 average
Aura of Silence
4 copies - 2 average
Engineered Plague
4 copies - 2 average
Argivian Find
4 copies - 2 average
Red Elemental Blast
4 copies - 2 average
Crumble
4 copies - 2 average
Duress
4 copies - 2 average
Ray of Revelation
4 copies - 2 average
Pyroclasm
3 copies - 1.5 average
Armageddon
3 copies - 1.5 average
Zuran Orb
2 copies - 1 average