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

Coinmama has become a reputable and reliable option for beginners looking to purchase bitcoin and ethereum. It has an easy to use interface, the option of instant purchasing via credit cards, and real time customer service. These reasons make it a very attractive option for people looking to get in to the world of cryptocurrencies easily.
Coinmama has a number of considerable disadvantages though. The very high fees, that can amount to 10%, on credit card purchases, are the main one. (There are no other funding options) They also don’t offer a wallet service, have no mobile application, or any additional trading tools.
Registering for an account on Coinmama is simple and straightforward. There is also a verification process, but it tends to be much shorter and less time consuming than other exchanges.
After users have opened an account and purchased bitcoin or ethereum, the funds are instantly transferred to a third-party wallet. This makes Coinmama very secure, as there is little chance of a breach.
Coinmama is able to process credit card payments because they require personal information and a government-issued ID. Furthermore, the privacy policy is very draconian; they reserve the right to obtain credit information about users before allowing them to purchase on the exchange and collect as much private information about users as they deem necessary before allowing them to purchase.
Despite this fact, it provides a basic on-ramp for users looking to buy bitcoin and ethereum for the first time.

Coinbase is one of the most prominent and influential crytpo companies. It is the most recognizable exchange in the United States and has over 20 million users worldwide.It is extremely user-friendly and is great for beginners. Coinbase is the intro platform for many first time crypto investors because it has a number of features such a free GDAX account for all users, a user friendly mobile App,  and built in wallet options.
There are a variety of security measures, and all funds are insured by the FDIC up to $250,000. Because of this, Coinbase is a very secure and reliable exchange with a reputable brand name
Its' clean and simple platform make it easy to quickly buy or sell cryptocurrency, and track funds through individual currency wallets.
Coinbase is a fully regulated exchange that is compliant with all laws, and because of their size and brand, they have been the subject of IRS investigations in which they were forced to disclose trading information for thousands of user accounts. They openly track user details and trading information. and have been known to close accounts for violating the terms and conditions.This is one of the main reasons that some traders prefer to use another exchange when they have become more familiar with the crypto ecosystem.
Coinbase also has  a relatively small amount of currency pairings and the platform does not have tools to accommodate more advance technical traders.
Coinbase also offers a variety of funding methods that make it an attractive choice for US residents that want to start buying crptocurrencies.Accounts can be easily funded. Since Coinbase is regulated, US bank accounts can be directly linked. This allows for relatively easy deposits and withdrawals, with a flat fee of 1.5% for buying via a US account. The trading fee is 0.25%