Bittrex is one of the largest crypto to crypto exchanges. It offers a large number of trading pairs, but do not allow fiat to crypto trading. Bittrex has one of the largest trading volumes in the market.
It is a reputable exchange with good record on security and is also fully regulated. They provide two factor authentication as well as a number of other options to secure funds. They are United States based and are fully compliant with all laws.
They support more than 190 cryptocurrencies and have a dynamic platform. It’s a good option for both advanced and beginner traders; providing advanced tools like candlestick charts and crosshairs, but with a user-friendly interface that is very intuitive.
Trading Fees: 0.25%

TopBTC is an exchange that has received varying reviews. Although TopBTC is known for having large trading volumes, the customer support is lacking and there are a variety of dead coins being traded. The company claims to be from Australia, but unlike other crypto currencies there, it is not a member of the Australian Digital Commerce Association(ADCA). TopBTC has also had many users claim that they were unable to withdraw funds.

Trading Fee: 0.2%
Withdrawal Fee: 0
Number of Tokens/Coins: 26