I would guess that it would be between the US with Epic, Irrational games, Rockstar, Bethesda, Valve, Bioware, Infinity Ward, Bungie, and a ton more that I can't think of and Japan with Capcom,Team Ninja, Square Enix, Konami, Nintendo, and another ton more that I forgot about.  What do you guys think?  I would guess that mostly every hardcore gamer would side with Japan, but at the same time some of their franchises are getting outdated. Don't get mad if I missed your favorite company, you can just put it in your post. (Blizzard might be a US company so correct me if I'm wrong) 

Ever since I was gaming Japan was the best. Still is for the most part.

I don't like this question

I wouldn't really know where all the companies are located.

the UK would be another good guess (even though they might not have that many studios, they should still have some good ones).

The UK has some brill studios and of course Japan, US and Amsterdam/Netherlands because of Guerrilla Games

Um... Japan? I think so at least.

Still Japan

are youguys serious about Japan? Yeah every gen before this they were but this gen they are failing HARD.

I would say the USA simply because the sheer number of AAA studios but the UK isn't bad either. I think Japan would be 3rd this gen because there are still some solid ones like Capcom and Kojima Productions.

Yeah I'd go with US for sure, all the studios OP mentioned plus Insomniac, Naughty Dog, Blizzard, etc

i have to say england, thats where rare is located :)