Most played cards in BG Midrange:

2 Decks
Sinkhole
8 copies - 4 average
Elves of Deep Shadow
8 copies - 4 average
Bayou
8 copies - 4 average
Hymn to Tourach
8 copies - 4 average
Erhnam Djinn
8 copies - 4 average
Hypnotic Specter
8 copies - 4 average
Crumble
7 copies - 3.5 average
Paralyze
7 copies - 3.5 average
Ice Storm
7 copies - 3.5 average
City of Brass
6 copies - 3 average
Terror
5 copies - 2.5 average
Gloom
5 copies - 2.5 average
Tsunami
4 copies - 2 average
Icy Manipulator
4 copies - 2 average
Scavenger Folk
4 copies - 2 average
Pendelhaven
4 copies - 2 average
Mishra's Factory
3 copies - 1.5 average
Nevinyrral's Disk
3 copies - 1.5 average
Su-Chi
2 copies - 1 average
Drain Life
2 copies - 1 average