KuCoin is a crytpo-to-crypto exchange that offers traders a reward system through its KuCoin Shares token. Kucoin has a wide variety of cryptocurrencies listed and has a reputation as an early adopter of many tokens. This provides good opportunities for investing in coins and tokens that re relatively new to crypto markets.
KuCoins's native cryptocurrency, KuCoin Shares (KCS), gives holders up to a 30% discount on trading fees, and entitles holders to receive dividends from all trading fees that are collected on the exchange. KuCoin distributes 50% of all trading fee revenues from the platform.

Withdrawal Fee: 0.0005 BTC and 0.01 ETH
Trading Fee: 0.1%
Number of Markets: 377

Gate.io is a crypto to crypto exchange based in the USA. It is an unregulated exchange and does not accept US clients. They offer one of the widest selections of tokens.

Trading Fee: 0.2%
Withdrawal Fee: 0.01 BTC, 0.03 ETH
Number of Tokens/Coins: 347

Gate.io has received many negative reviews regarding difficulties withdrawing funds.

Poloniex is an established crypto to crypto exchange that is based in the United States. It offers a large selection of tokens to trade and has high liquidity. Poloniex was hacked in 2014, and lost more than 12% of their bitcoin supply. They have improved their security protocols since then. In February, 2018 Poloniex was acquired by Circle, one of the largest crypto payment providers.

Trading Fee: 0%-0.1% Maker and 0%-0.2% Taker
Deposit Fee: Varying Depending on blockchain fees
Withdrawal Fee: Varying Depending on blockchain fees
Number of Tokens/Coins: 97