Buying bitcoin with your bank account or bank transfer can be a good way to buy Bitcoin in VERY large amounts.
Coinbase is one of the most popular ways to buy bitcoin with your bank account in the USA, Europe, Canada, Singapore, and Australia.
With a backup credit card attached, you can buy a lot of bitcoins instantly. Coinbase does charge 1.49% fees, which is more than Circle (more below), but does have higher limits than Circle.
Gemini is a great option for US users to buy with a bank account. Gemini also supports the United Kingdom, Canada, Singapore, Hong Kong, and also Japan.
Kraken is the world’s leader in EUR trading volume, making it a great option for all Europeans. It is a great way to purchase bitcoins with your bank account or bank transfer.
Bitstamp is the longest running Bitcoin exchange. You can make an international SWITF wire transfer to Bitstamp in order to fund your exchange account.