Most played cards in Glimpse of Tomorrow:

4 Decks
Shardless Agent
16 copies - 4 average
Violent Outburst
15 copies - 3.75 average
Khalni Garden
15 copies - 3.75 average
Wavesifter
15 copies - 3.75 average
Fury
15 copies - 3.75 average
Misty Rainforest
14 copies - 3.5 average
Wooded Foothills
13 copies - 3.25 average
Scalding Tarn
13 copies - 3.25 average
Glimpse of Tomorrow
13 copies - 3.25 average
Omnath, Locus of Creation
12 copies - 3 average
Subtlety
11 copies - 2.75 average
Endurance
10 copies - 2.5 average
Foundation Breaker
9 copies - 2.25 average
Mystical Dispute
9 copies - 2.25 average
Cavern of Souls
8 copies - 2 average
Goblin Dark-Dwellers
8 copies - 2 average
Fable of the Mirror-Breaker
8 copies - 2 average
Risen Reef
8 copies - 2 average
Chancellor of the Forge
7 copies - 1.75 average
Twinshot Sniper
7 copies - 1.75 average