Most played cards in Workshops:

1 Decks
Walking Ballista
4 copies - 4 average
Grafdigger's Cage
4 copies - 4 average
Wurmcoil Engine
4 copies - 4 average
Sphere of Resistance
4 copies - 4 average
Nettlecyst
4 copies - 4 average
Ancient Tomb
4 copies - 4 average
Foundry Inspector
4 copies - 4 average
Phyrexian Revoker
4 copies - 4 average
Mishra's Workshop
4 copies - 4 average
Wasteland
4 copies - 4 average
Urza's Saga
4 copies - 4 average
Arcbound Ravager
4 copies - 4 average
Surgical Extraction
3 copies - 3 average
Sol Ring
1 copies - 1 average
Skysovereign, Consul Flagship
1 copies - 1 average
Mystic Forge
1 copies - 1 average
Thorn of Amethyst
1 copies - 1 average
Mox Sapphire
1 copies - 1 average
Crucible of Worlds
1 copies - 1 average
Pithing Needle
1 copies - 1 average