Most played cards in U/G Madness:

1 Decks
Chill
4 copies - 4 average
Wild Mongrel
4 copies - 4 average
Arrogant Wurm
4 copies - 4 average
Yavimaya Coast
4 copies - 4 average
Careful Study
4 copies - 4 average
Basking Rootwalla
4 copies - 4 average
Aquamoeba
3 copies - 3 average
Daze
3 copies - 3 average
Oxidize
3 copies - 3 average
Deep Analysis
3 copies - 3 average
Waterfront Bouncer
3 copies - 3 average
Gilded Drake
2 copies - 2 average
Submerge
2 copies - 2 average
Arcane Laboratory
2 copies - 2 average
Merfolk Looter
2 copies - 2 average
Wonder
2 copies - 2 average
Chrome Mox
2 copies - 2 average
Roar of the Wurm
2 copies - 2 average
Ray of Revelation
1 copies - 1 average
Intuition
1 copies - 1 average