Most played cards in Junk:

6 Decks
Brainstorm
24 copies - 4 average
Ponder
24 copies - 4 average
Force of Will
24 copies - 4 average
Wasteland
19 copies - 3.17 average
Polluted Delta
19 copies - 3.17 average
Underground Sea
16 copies - 2.67 average
Daze
16 copies - 2.67 average
Dragon's Rage Channeler
16 copies - 2.67 average
Force of Negation
15 copies - 2.5 average
Murktide Regent
14 copies - 2.33 average
Pyroblast
14 copies - 2.33 average
Mishra's Bauble
14 copies - 2.33 average
Volcanic Island
13 copies - 2.17 average
Psychic Frog
12 copies - 2 average
Orcish Bowmasters
12 copies - 2 average
Lightning Bolt
12 copies - 2 average
Scalding Tarn
11 copies - 1.83 average
Flooded Strand
10 copies - 1.67 average
Tamiyo, Inquisitive Student
8 copies - 1.33 average
Misty Rainforest
7 copies - 1.17 average