Most played cards in U/B Beats:

3 Decks
Watery Grave
12 copies - 4 average
Shadowmage Infiltrator
12 copies - 4 average
Snow-Covered Island
11 copies - 3.67 average
Last Gasp
11 copies - 3.67 average
Deathmark
8 copies - 2.67 average
Psionic Blast
8 copies - 2.67 average
Dark Confidant
8 copies - 2.67 average
Underground River
8 copies - 2.67 average
Darkblast
8 copies - 2.67 average
Repeal
8 copies - 2.67 average
Remand
8 copies - 2.67 average
Mana Leak
7 copies - 2.33 average
Cancel
5 copies - 1.67 average
Snow-Covered Swamp
5 copies - 1.67 average
Voidmage Prodigy
5 copies - 1.67 average
Looter il-Kor
4 copies - 1.33 average
Dauthi Slayer
4 copies - 1.33 average
4 copies - 1.33 average
Sudden Death
4 copies - 1.33 average
Hypnotic Specter
4 copies - 1.33 average