Japan, China, USA, UK and Netherlands.These countries have different features that could make of them a good place for Bitcoin to spread. Regulations are soft, technology penetration is high and Bitcoin businesses are growing fast. Bitcoin and cryptocurrency communities are also strong in those countries, different meetings and start-ups are pushing the Bitcoin environment to the next level.
While BTC communities and knowledge in strong in these countries I am afraid UK while it's unregulated and Legal but impossible to get a Bank Account for Bitcoin Trading, Crypto Trading or anything with the name of Digital Currencies.
UK an amazing place for this but the Bank's won't support it been there and have tried over 3 months to get a business account impossible especially with over 10 year track record with the banks!!!