Most played cards in Grixis Aggro:

2 Decks
Deathrite Shaman
8 copies - 4 average
Delver of Secrets
8 copies - 4 average
Daze
8 copies - 4 average
Brainstorm
8 copies - 4 average
Wasteland
8 copies - 4 average
Force of Will
8 copies - 4 average
Flooded Strand
8 copies - 4 average
Lightning Bolt
8 copies - 4 average
Gitaxian Probe
8 copies - 4 average
Young Pyromancer
7 copies - 3.5 average
Ponder
7 copies - 3.5 average
Volcanic Island
6 copies - 3 average
Cabal Therapy
6 copies - 3 average
Gurmag Angler
4 copies - 2 average
Polluted Delta
4 copies - 2 average
Underground Sea
4 copies - 2 average
Surgical Extraction
4 copies - 2 average
Scalding Tarn
4 copies - 2 average
Diabolic Edict
3 copies - 1.5 average
Ancient Grudge
3 copies - 1.5 average