Bitstamp is one of the most popular fiat to Bitcoin exchanges. It was one of the first big exchanges and it provides customers with a platform that is secure and easy to use. It was originally started in Slovenia but has moved its' operations to Luxembourg.
Bitstamp uses MultiSignature technology for its hot-wallet, as well as a fully insured cold-storage option where kept off-line. They also offer a number of other security features such as two-factor authentication and confirmation emails to enhance account security.
Bitstamp provides the option for limit orders, stop loss, and trailing stop orders. They have an easy to use API that can be integrated into user applications. T
Overall, Bitstamp is a secure and reliable exchange with good liquidity and a solid infrastructure. It is a good option for beginning traders as well as more advanced crypto holders.
Trading Fees: Tiered system depending on volume ranging from 0.1%-025%

Huobi is one of the world's leading trading platform, committed to providing investors with a professional, safe and honest transaction services. The Exchange charges no deposit fees but does have an exit fee of between 1% and 2%. It was originally based in China, but moved its' headquarters to Singapore, and also has offices in Hong Kong, Korea, Japan and the United States.
Huobi has raised capital from investors including Dai Zhikang, Sequoia Capital and Zhen Fund. Huobi is a major player in the Chinese blockchain scene. It runs a mining pool, (Huobi Pool) incubator, (Huobi Labs) and a research institution. (Huobi Academy of Blockchain Applications)
Trading fee of 0.2%

CEX.io is a British company that changed its focus from mining into becoming a cryptocurrency exchange. CEX has made an effort to add many coins, and boasts of fill-or-kill (FOK) orders that allow for some of the industry’s fastest trading, but it has a poor record on privacy and transparency that should give pause to traders.
The exchange’s fill-or-kill (FOK) orders are very fast, but come at a steep 7% fee. The mobile application is easy to use, and there is also an API integration. CEX is a regulated exchange that complies with all KYC and ALM laws, so they are able to accommodate several funding options, including credit cards and bank transfers.
The majority of CEX.io’s trading volume is done with bitcoin, and although they have made an effort to add more coins, this exchange simply does not have the trading options that others do. The low trading volume of other major coins provides limited liquidity for most traders.
Trading fees vary depending on trading volume between 0.16%-0.25%.Bank transfers are free and withdrawal fees are lower compared to their competitors, but transfers can take up to 20 days.
Although CEX.io is easy to use and allows for very fast crypto purchases, it has high fees, delayed withdrawal times, and a poor record on privacy/transparency.