Most played cards in Esper:

2 Decks
Tundra
8 copies - 4 average
Disenchant
8 copies - 4 average
Serendib Efreet
7 copies - 3.5 average
Swords to Plowshares
7 copies - 3.5 average
Underground Sea
6 copies - 3 average
Mishra's Factory
4 copies - 2 average
Serra Angel
4 copies - 2 average
City of Brass
4 copies - 2 average
Divine Offering
4 copies - 2 average
Control Magic
4 copies - 2 average
Dust to Dust
4 copies - 2 average
Moat
4 copies - 2 average
Order of Leitbur
4 copies - 2 average
Savannah Lions
4 copies - 2 average
Power Sink
3 copies - 1.5 average
Blue Elemental Blast
3 copies - 1.5 average
Circle of Protection: Red
3 copies - 1.5 average
Fellwar Stone
3 copies - 1.5 average
Counterspell
3 copies - 1.5 average
Aeolipile
3 copies - 1.5 average