UNUS SED LEO is an initiative started by Bitfinex that is focused on increasing the exchange's transparency. UNUS SED LEO means "one, but it's a lion" in Latin. The iniatative was created to increase the transparency of the exchange's finances, following a controversy related to the allocation of reserves from the stablecoin Tether, that was created by the same parent company as the Bitfinex exchange, iFinex. It is built around a token burning redemption mechanism which is tied to the parent company's revenues. Their dashboard provides insights into the fees that are collected, and the LEO tokens that are burned.

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

Kraken is a US-based cryptocurrency exchange and one of the largest bitcoin exchanges in terms of volume and liquidity.
It provides Bitcoin pricing to the Bloomberg Terminal and has considerable influence on the overall crypto market. Kraken offers a number fiat funding and transfer options.
There are 18 BTC pairs and 16 USD pair to trade
Fees vary depending on the volume - for main trading pairs this is between 0.1-0.35% - however for other less common crypto pairs the range can be as low as 0.05% or as high as 0.75%. There are also 0% fees for some trades.
Withdrawals and deposits are variable depending on the method - although in general all fees are 0.19% with a $20 minimum.