Most played cards in Storm:

5 Decks
Lotus Petal
20 copies - 4 average
Burning Wish
16 copies - 3.2 average
Lion's Eye Diamond
16 copies - 3.2 average
Rite of Flame
12 copies - 2.4 average
Dark Ritual
12 copies - 2.4 average
Ponder
12 copies - 2.4 average
Brainstorm
12 copies - 2.4 average
Polluted Delta
10 copies - 2 average
Cabal Ritual
8 copies - 1.6 average
Thoughtseize
8 copies - 1.6 average
Ancient Tomb
8 copies - 1.6 average
Infernal Tutor
8 copies - 1.6 average
Galvanic Relay
8 copies - 1.6 average
Chrome Mox
7 copies - 1.4 average
Empty the Warrens
7 copies - 1.4 average
Tendrils of Agony
7 copies - 1.4 average
Duress
7 copies - 1.4 average
Mox Opal
7 copies - 1.4 average
Wishclaw Talisman
6 copies - 1.2 average
Veil of Summer
6 copies - 1.2 average