Most played cards in Thassa, God of the Sea:

2 Decks
Orbs of Warding
2 copies - 1 average
Oblivion Stone
2 copies - 1 average
Pithing Needle
2 copies - 1 average
Forcefield
2 copies - 1 average
Sapphire Medallion
2 copies - 1 average
Vedalken Shackles
2 copies - 1 average
Thaumatic Compass
2 copies - 1 average
Sorcerous Spyglass
2 copies - 1 average
Expedition Map
2 copies - 1 average
Whir of Invention
2 copies - 1 average
Psionic Blast
2 copies - 1 average
Pact of Negation
2 copies - 1 average
Opt
2 copies - 1 average
Reweave
2 copies - 1 average
Spell Pierce
2 copies - 1 average
Turnabout
2 copies - 1 average
Supreme Will
2 copies - 1 average
Omniscience
2 copies - 1 average
Arch of Orazca
2 copies - 1 average
Myriad Landscape
2 copies - 1 average