Most played cards in B/R Aggro:

1 Decks
Sinkhole
4 copies - 4 average
Stone Rain
4 copies - 4 average
Badlands
4 copies - 4 average
Red Elemental Blast
4 copies - 4 average
Dark Ritual
4 copies - 4 average
Black Vise
4 copies - 4 average
Lightning Bolt
4 copies - 4 average
Hypnotic Specter
4 copies - 4 average
Black Knight
4 copies - 4 average
Terror
2 copies - 2 average
Gloom
2 copies - 2 average
Paralyze
2 copies - 2 average
Sengir Vampire
2 copies - 2 average
Shatter
2 copies - 2 average
Earthquake
1 copies - 1 average
Black Lotus
1 copies - 1 average
Icy Manipulator
1 copies - 1 average
Fireball
1 copies - 1 average
Demonic Tutor
1 copies - 1 average
Disintegrate
1 copies - 1 average