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%

Bithumb is the biggest Korean crypto exchange. It is a top 30 exchange by trading volume and it is one of the most significant blockchain companies in South Korea. In June, 2018, Bithumb was hacked and around $870,000 in bitcoin were stolen from customers.
Trading Fee: 0.15%
Withdrawal Fee: 0.001 BTC
Number of Tokens/Coins: 32

OEX is a top 30 exchange with increasing trading volumes. The token selection is not large and includes some tokens that are not listed on many other exchanges.

Trading Fee: 0.2%
Withdrawal Fee: 0
Number of Tokens/Coins: 13