Most played cards in UW Skies:

3 Decks
Serra Angel
12 copies - 4 average
Swords to Plowshares
12 copies - 4 average
Tundra
12 copies - 4 average
Counterspell
12 copies - 4 average
Disenchant
12 copies - 4 average
Blue Elemental Blast
11 copies - 3.67 average
Fellwar Stone
8 copies - 2.67 average
Divine Offering
8 copies - 2.67 average
Azure Drake
8 copies - 2.67 average
Maze of Ith
8 copies - 2.67 average
Desert
8 copies - 2.67 average
Wrath of God
7 copies - 2.33 average
City of Brass
7 copies - 2.33 average
Jayemdae Tome
6 copies - 2 average
Serendib Efreet
4 copies - 1.33 average
Diamond Valley
4 copies - 1.33 average
Plateau
4 copies - 1.33 average
Circle of Protection: Red
4 copies - 1.33 average
Lightning Bolt
4 copies - 1.33 average
Psionic Blast
4 copies - 1.33 average