Most played cards in Sneak Attack:

3 Decks
Gamble
12 copies - 4 average
Sneak Attack
12 copies - 4 average
Serra Avatar
12 copies - 4 average
Sandstone Needle
12 copies - 4 average
Seething Song
12 copies - 4 average
Through the Breach
12 copies - 4 average
Chrome Mox
12 copies - 4 average
Crystal Vein
11 copies - 3.67 average
City of Traitors
11 copies - 3.67 average
Defense Grid
8 copies - 2.67 average
Dwarven Ruins
8 copies - 2.67 average
Pyrostatic Pillar
7 copies - 2.33 average
Symbiotic Wurm
7 copies - 2.33 average
Arc-Slogger
7 copies - 2.33 average
Dragon Tyrant
6 copies - 2 average
5 copies - 1.67 average
Rorix Bladewing
5 copies - 1.67 average
Final Fortune
5 copies - 1.67 average
Fling
4 copies - 1.33 average
Darksteel Colossus
4 copies - 1.33 average