Most played cards in Combo:

1 Decks
Surge Engine
4 copies - 4 average
Force of Will
4 copies - 4 average
Agatha's Soul Cauldron
4 copies - 4 average
Consign to Memory
3 copies - 3 average
Urza's Saga
3 copies - 3 average
Ancient Tomb
3 copies - 3 average
Baleful Strix
3 copies - 3 average
Goblin Engineer
3 copies - 3 average
Opposition Agent
3 copies - 3 average
Polluted Delta
3 copies - 3 average
Lotus Petal
3 copies - 3 average
Walking Ballista
3 copies - 3 average
Metallic Rebuke
2 copies - 2 average
Surgical Extraction
2 copies - 2 average
Orcish Bowmasters
2 copies - 2 average
Fatal Push
2 copies - 2 average
Tamiyo, Inquisitive Student
2 copies - 2 average
Underground Sea
2 copies - 2 average
Scalding Tarn
2 copies - 2 average
Prismari Command
1 copies - 1 average