Most played cards in Hammertime:

2 Decks
Snow-Covered Plains
19 copies - 9.5 average
Colossus Hammer
8 copies - 4 average
Urza's Saga
8 copies - 4 average
Drannith Magistrate
8 copies - 4 average
Sigarda's Aid
8 copies - 4 average
Esper Sentinel
8 copies - 4 average
Stoneforge Mystic
8 copies - 4 average
Ornithopter
8 copies - 4 average
Puresteel Paladin
8 copies - 4 average
March of Otherworldly Light
6 copies - 3 average
Inkmoth Nexus
6 copies - 3 average
Silent Clearing
5 copies - 2.5 average
Memnite
4 copies - 2 average
Blacksmith's Skill
4 copies - 2 average
Mana Tithe
3 copies - 1.5 average
Steelshaper's Gift
3 copies - 1.5 average
Portable Hole
3 copies - 1.5 average
Paradise Mantle
3 copies - 1.5 average
Pithing Needle
2 copies - 1 average
Sanctifier en-Vec
2 copies - 1 average