Most played cards in Tron:

3 Decks
Urza's Tower
12 copies - 4 average
Urza's Power Plant
12 copies - 4 average
Triskelion
12 copies - 4 average
Urza's Mine
12 copies - 4 average
Su-Chi
8 copies - 2.67 average
Mishra's Factory
8 copies - 2.67 average
Juggernaut
8 copies - 2.67 average
Howling Mine
7 copies - 2.33 average
Relic Barrier
7 copies - 2.33 average
Winter Orb
6 copies - 2 average
Mishra's Workshop
5 copies - 1.67 average
Icy Manipulator
4 copies - 1.33 average
Brass Man
4 copies - 1.33 average
Candelabra of Tawnos
4 copies - 1.33 average
Hymn to Tourach
4 copies - 1.33 average
Desert
4 copies - 1.33 average
Black Vise
4 copies - 1.33 average
Rocket Launcher
4 copies - 1.33 average
Initiates of the Ebon Hand
4 copies - 1.33 average
Drain Life
4 copies - 1.33 average