Most played cards in Intruder Alarm:

2 Decks
Sakura-Tribe Elder
8 copies - 4 average
Birds of Paradise
8 copies - 4 average
Echoing Truth
7 copies - 3.5 average
City of Brass
7 copies - 3.5 average
Intruder Alarm
7 copies - 3.5 average
Forbidden Orchard
6 copies - 3 average
Time of Need
6 copies - 3 average
Sensei's Divining Top
4 copies - 2 average
Boil
4 copies - 2 average
Mana Leak
4 copies - 2 average
Defense Grid
4 copies - 2 average
Eternal Witness
4 copies - 2 average
Aether Vial
4 copies - 2 average
Kodama of the North Tree
4 copies - 2 average
Kiki-Jiki, Mirror Breaker
4 copies - 2 average
Sylvan Scrying
3 copies - 1.5 average
Tendo Ice Bridge
3 copies - 1.5 average
Chrome Mox
3 copies - 1.5 average
Iwamori of the Open Fist
3 copies - 1.5 average
Trinket Mage
3 copies - 1.5 average