Most played cards in B/W Aggro:

2 Decks
Spectral Procession
8 copies - 4 average
Burrenton Forge-Tender
8 copies - 4 average
Steppe Lynx
8 copies - 4 average
Blood Moon
8 copies - 4 average
Tidehollow Sculler
8 copies - 4 average
Thoughtseize
8 copies - 4 average
Path to Exile
8 copies - 4 average
Marsh Flats
8 copies - 4 average
Figure of Destiny
8 copies - 4 average
Arid Mesa
8 copies - 4 average
Godless Shrine
8 copies - 4 average
Pithing Needle
8 copies - 4 average
Umezawa's Jitte
8 copies - 4 average
Kitchen Finks
8 copies - 4 average
Kataki, War's Wage
5 copies - 2.5 average
Soltari Priest
4 copies - 2 average
Honor of the Pure
4 copies - 2 average
Isamaru, Hound of Konda
4 copies - 2 average
Sacred Foundry
2 copies - 1 average
1 copies - 0.5 average