Most played cards in Boros Deck Wins:

2 Decks
Lightning Helix
8 copies - 4 average
Mogg Fanatic
8 copies - 4 average
Incinerate
8 copies - 4 average
Sacred Foundry
7 copies - 3.5 average
Silver Knight
7 copies - 3.5 average
Char
6 copies - 3 average
Kataki, War's Wage
6 copies - 3 average
Umezawa's Jitte
6 copies - 3 average
Flooded Strand
6 copies - 3 average
Isamaru, Hound of Konda
5 copies - 2.5 average
Molten Rain
4 copies - 2 average
Windswept Heath
4 copies - 2 average
Figure of Destiny
4 copies - 2 average
Volcanic Fallout
4 copies - 2 average
Soltari Priest
4 copies - 2 average
Pyrostatic Pillar
4 copies - 2 average
Kitchen Finks
4 copies - 2 average
Jötun Grunt
4 copies - 2 average
Countryside Crusher
4 copies - 2 average
Battlefield Forge
4 copies - 2 average