Most played cards in Rogue:

2 Decks
Mishra's Factory
8 copies - 4 average
Badlands
8 copies - 4 average
Sedge Troll
8 copies - 4 average
Nevinyrral's Disk
6 copies - 3 average
Lightning Bolt
6 copies - 3 average
Red Elemental Blast
5 copies - 2.5 average
Earthquake
5 copies - 2.5 average
Terror
5 copies - 2.5 average
Power Surge
4 copies - 2 average
Granite Gargoyle
4 copies - 2 average
Underground Sea
4 copies - 2 average
City of Brass
4 copies - 2 average
Uthden Troll
4 copies - 2 average
Hypnotic Specter
4 copies - 2 average
Plateau
4 copies - 2 average
Volcanic Island
4 copies - 2 average
Serendib Efreet
4 copies - 2 average
Gloom
3 copies - 1.5 average
Blue Elemental Blast
2 copies - 1 average
City in a Bottle
2 copies - 1 average