BitFinex is a bitcoin to fiat exchange, a margin trading exchange, and a liquidity provider. The platform offers a number of features that expand the financial positions you can take - for example the ability to short Bitcoin via margin trading.
The exchange also offers a set of other cryptos apart from bitcoin such as Litecoin and Ethereum.
Deposits and withdrawals take place via the standard bank transfer means with fees of 0.1% and a minimum of $20. Bitcoin and Litecoin are free.
BitFinex takes security seriously and have moved from a hot wallet cold wallet set up to segregating customer funds where each user has access to their own wallet which they can review on the blockchain.
Bitfinex was hacked on 03 August 2016 and around 120,000 BTC were stolen.
Fee of 0.1% for most trades

Bitbank is a regulated fiat to crypto exchange that is based in Japan. It currently does not have any trading fees. Bitbank is one of the largest Japanese cryptocurrency platforms, and ranks in the top 30 exchanges for total trading volume. Bitbank also offers several other crypto services in Japan.

Trading Fee: 0
Withdrawal Fee: 0.001 BTC, 0.001 ETH
Number of Markets: 8

Bancor is a decentralized exchange protocol that is designed to increase liquidity for Ethereum and EOS tokens. The company has been at the center of the debate about Decentralized vs Centralized Exchanges, as well as the overall need of institutions to serve as a hub for decentralized networks. Their protocol, and exchange, enable any token to hold one or other additional tokens in reserve. Bancor allows conversions between tokens on their decentralized exchange with smart tokens that increase liquidity, and establish market prices for smaller tokens. Specifically, for those that do not have large trading volumes. Bancor tokens facilitate the exchange and act as a connective tissue, and have a centralizing effect on the exchange.