Most played cards in Faeries:

4 Decks
Underground River
16 copies - 4 average
Faerie Conclave
14 copies - 3.5 average
Cryptic Command
13 copies - 3.25 average
Spellstutter Sprite
12 copies - 3 average
Mistbind Clique
12 copies - 3 average
Thoughtseize
12 copies - 3 average
Secluded Glen
12 copies - 3 average
Snow-Covered Island
10 copies - 2.5 average
Sower of Temptation
9 copies - 2.25 average
Snow-Covered Swamp
9 copies - 2.25 average
Rune Snag
8 copies - 2 average
Bitterblossom
8 copies - 2 average
8 copies - 2 average
Scion of Oona
8 copies - 2 average
Mutavault
8 copies - 2 average
Vendilion Clique
7 copies - 1.75 average
River of Tears
6 copies - 1.5 average
Sunken Ruins
5 copies - 1.25 average
Shriekmaw
4 copies - 1 average
Vivid Creek
4 copies - 1 average