Most played cards in Dredge:

2 Decks
Stinkweed Imp
8 copies - 4 average
Putrid Imp
8 copies - 4 average
Polluted Delta
8 copies - 4 average
Narcomoeba
8 copies - 4 average
Golgari Grave-Troll
8 copies - 4 average
Cephalid Coliseum
8 copies - 4 average
Bridge from Below
8 copies - 4 average
Chain of Vapor
8 copies - 4 average
Careful Study
8 copies - 4 average
Pithing Needle
7 copies - 3.5 average
Watery Grave
7 copies - 3.5 average
Ichorid
7 copies - 3.5 average
Breakthrough
7 copies - 3.5 average
Gemstone Mine
7 copies - 3.5 average
Golgari Thug
6 copies - 3 average
Cabal Therapy
6 copies - 3 average
Leyline of the Void
4 copies - 2 average
Dread Return
4 copies - 2 average
4 copies - 2 average
Firemane Angel
4 copies - 2 average