Ask HN: What is the best exchange to buy cryptocurrency in your country (+why)?

I'm in the US, and I have purchased all my cryptocurrency through Coinbase. Was that a mistake? If so, why? I'm thinking about fees, flexibility, safety, etc. And, what are the best options in other countries? I'm assuming MtGox would be low on the list for Japan. (I'm not so familiar with Ask HN, but would it work to start a thread with the just the exchange name and countr(ies), and then add comments on the why in the thread below? That way it is easy to do a quick vote and then read the conversation below if you are interested.)