Most played cards in Sneak Red:

2 Decks
Simian Spirit Guide
8 copies - 4 average
Sneak Attack
8 copies - 4 average
Trinisphere
8 copies - 4 average
Ancient Tomb
8 copies - 4 average
Lotus Petal
8 copies - 4 average
City of Traitors
8 copies - 4 average
Through the Breach
7 copies - 3.5 average
Emrakul, the Aeons Torn
7 copies - 3.5 average
Griselbrand
7 copies - 3.5 average
Seething Song
6 copies - 3 average
Show and Tell
4 copies - 2 average
Elvish Spirit Guide
4 copies - 2 average
Faerie Macabre
4 copies - 2 average
Scalding Tarn
4 copies - 2 average
Worldspine Wurm
4 copies - 2 average
Karn, the Great Creator
4 copies - 2 average
Abrade
4 copies - 2 average
Chalice of the Void
4 copies - 2 average
Blood Sun
4 copies - 2 average
Boseiju, Who Shelters All
2 copies - 1 average