Most played cards in Combo/Aggro:

1 Decks
Chain Lightning
4 copies - 4 average
Badlands
4 copies - 4 average
Mishra's Factory
4 copies - 4 average
Power Surge
4 copies - 4 average
Terror
4 copies - 4 average
Lightning Bolt
4 copies - 4 average
Sedge Troll
4 copies - 4 average
Hypnotic Specter
4 copies - 4 average
Order of the Ebon Hand
3 copies - 3 average
Shatterstorm
2 copies - 2 average
Stone Rain
2 copies - 2 average
Red Elemental Blast
2 copies - 2 average
Gloom
2 copies - 2 average
Vampire Bats
2 copies - 2 average
Flashfires
2 copies - 2 average
City of Brass
2 copies - 2 average
Granite Gargoyle
2 copies - 2 average
Disintegrate
2 copies - 2 average
Fellwar Stone
2 copies - 2 average
Pyrotechnics
2 copies - 2 average