Most played cards in Tron:

1 Decks
Urza's Tower
4 copies - 4 average
Brass Man
4 copies - 4 average
Urza's Power Plant
4 copies - 4 average
Mishra's Factory
4 copies - 4 average
Hymn to Tourach
4 copies - 4 average
Terror
4 copies - 4 average
Urza's Mine
4 copies - 4 average
Drain Life
4 copies - 4 average
Triskelion
4 copies - 4 average
Relic Barrier
4 copies - 4 average
Initiates of the Ebon Hand
4 copies - 4 average
Priest of Yawgmoth
3 copies - 3 average
Sengir Vampire
3 copies - 3 average
Howling Mine
3 copies - 3 average
Animate Dead
2 copies - 2 average
The Rack
2 copies - 2 average
Sorceress Queen
2 copies - 2 average
Winter Orb
2 copies - 2 average
Xenic Poltergeist
1 copies - 1 average
Demonic Tutor
1 copies - 1 average