Most played cards in UR Aggro:

3 Decks
Chain Lightning
12 copies - 4 average
Lightning Bolt
12 copies - 4 average
Mishra's Factory
11 copies - 3.67 average
Red Elemental Blast
9 copies - 3 average
Electric Eel
8 copies - 2.67 average
City of Brass
7 copies - 2.33 average
Blue Elemental Blast
7 copies - 2.33 average
Psionic Blast
6 copies - 2 average
Black Vise
5 copies - 1.67 average
Fellwar Stone
5 copies - 1.67 average
Atog
4 copies - 1.33 average
Azure Drake
4 copies - 1.33 average
Ironclaw Orcs
4 copies - 1.33 average
Serendib Efreet
4 copies - 1.33 average
Ankh of Mishra
4 copies - 1.33 average
Repentant Blacksmith
4 copies - 1.33 average
Swords to Plowshares
4 copies - 1.33 average
Flying Men
4 copies - 1.33 average
Disenchant
4 copies - 1.33 average
Plateau
4 copies - 1.33 average