Most played cards in Gruul Aggro:

5 Decks
Lightning Bolt
20 copies - 4 average
Rugged Highlands
20 copies - 4 average
Pyroblast
15 copies - 3 average
Golgari Brownscale
12 copies - 2.4 average
Electrickery
12 copies - 2.4 average
Basking Rootwalla
12 copies - 2.4 average
Wild Mongrel
12 copies - 2.4 average
Werebear
12 copies - 2.4 average
Faithless Looting
11 copies - 2.2 average
Fiery Temper
9 copies - 1.8 average
Tranquility
9 copies - 1.8 average
Rancor
9 copies - 1.8 average
Evolving Wilds
9 copies - 1.8 average
Blastoderm
9 copies - 1.8 average
Arrogant Wurm
9 copies - 1.8 average
Nest Invader
8 copies - 1.6 average
Nettle Sentinel
8 copies - 1.6 average
Thermo-Alchemist
8 copies - 1.6 average
Scatter the Seeds
8 copies - 1.6 average
Khalni Garden
8 copies - 1.6 average