Most played cards in U/W Tron:

5 Decks
Urza's Tower
20 copies - 4 average
Hallowed Fountain
20 copies - 4 average
Azorius Signet
20 copies - 4 average
Urza's Power Plant
20 copies - 4 average
Adarkar Wastes
20 copies - 4 average
Urza's Mine
20 copies - 4 average
Wrath of God
19 copies - 3.8 average
Compulsive Research
19 copies - 3.8 average
Remand
16 copies - 3.2 average
Faith's Fetters
15 copies - 3 average
Circle of Protection: Red
12 copies - 2.4 average
Dimir Signet
12 copies - 2.4 average
Teferi, Mage of Zhalfir
11 copies - 2.2 average
Spell Burst
10 copies - 2 average
Mana Leak
10 copies - 2 average
Annex
10 copies - 2 average
Jester's Scepter
8 copies - 1.6 average
Tidings
8 copies - 1.6 average
Urza's Factory
8 copies - 1.6 average
7 copies - 1.4 average