People saying anything other than the US are really crazy, Sorry !!
If we are talking about the whole gaming industry then by far the US has been the greatest contributor and it's not even close. Even when the market was dominated by Japanese consoles who do you think designed the hardware Tech inside those console ? Who do you think created the first Video game, Arcade game, Game console ? Who do you think created the first 3D polygon and created real 3D graphics ? and lastly Who designed the CPU and GPU for all the consoles on the market today ?
The answer to above is the US clear and simple. Every genre that is poplar today was born by a US dev even RPGs the only genre Japan created is probably rape games !!
I'm telling you guys if you want to look at it in an objectively matter than any answer other than the US is a wrong answer, sorry.
