Most played cards in Dark Depths:

2 Decks
Verdant Catacombs
8 copies - 4 average
Urborg, Tomb of Yawgmoth
8 copies - 4 average
Satyr Wayfinder
8 copies - 4 average
Crop Rotation
8 copies - 4 average
Thoughtseize
8 copies - 4 average
Thespian's Stage
8 copies - 4 average
Vampire Hexmage
8 copies - 4 average
Dark Depths
8 copies - 4 average
Elvish Reclaimer
7 copies - 3.5 average
Mox Diamond
7 copies - 3.5 average
Surgical Extraction
6 copies - 3 average
Sylvan Safekeeper
6 copies - 3 average
Hogaak, Arisen Necropolis
6 copies - 3 average
Abrupt Decay
5 copies - 2.5 average
Force of Vigor
5 copies - 2.5 average
Pithing Needle
4 copies - 2 average
Cabal Therapy
4 copies - 2 average
Stitcher's Supplier
4 copies - 2 average
Bayou
4 copies - 2 average
Khalni Garden
3 copies - 1.5 average