Most played cards in Gruul:

2 Decks
Taiga
8 copies - 4 average
Lightning Bolt
8 copies - 4 average
Giant Growth
8 copies - 4 average
Kird Ape
8 copies - 4 average
Chain Lightning
8 copies - 4 average
Scryb Sprites
7 copies - 3.5 average
Argothian Pixies
6 copies - 3 average
Berserk
6 copies - 3 average
Erhnam Djinn
6 copies - 3 average
Llanowar Elves
5 copies - 2.5 average
City of Brass
5 copies - 2.5 average
Avoid Fate
5 copies - 2.5 average
Scavenger Folk
4 copies - 2 average
Red Elemental Blast
4 copies - 2 average
Black Vise
4 copies - 2 average
Whirling Dervish
4 copies - 2 average
Shatter
4 copies - 2 average
Elvish Archers
4 copies - 2 average
Sylvan Library
3 copies - 1.5 average
Pendelhaven
3 copies - 1.5 average