Most played cards in Uro, Wrath of the Genesis Storm:

2 Decks
Snow-Covered Island
30 copies - 15 average
Snow-Covered Forest
5 copies - 2.5 average
Merchant Scroll
2 copies - 1 average
Miscalculation
2 copies - 1 average
Opt
2 copies - 1 average
Noxious Revival
2 copies - 1 average
Mystic Confluence
2 copies - 1 average
Mission Briefing
2 copies - 1 average
Mental Misstep
2 copies - 1 average
Mana Vapors
2 copies - 1 average
Hieroglyphic Illumination
2 copies - 1 average
Growth Spiral
2 copies - 1 average
Gitaxian Probe
2 copies - 1 average
Impulse
2 copies - 1 average
Breeding Pool
2 copies - 1 average
Peek
2 copies - 1 average
Mana Leak
2 copies - 1 average
Intuition
2 copies - 1 average
Memory Lapse
2 copies - 1 average
Preordain
2 copies - 1 average