My best crypto exchange for 2021 is as follow,
1Binance: I have considered Binance as the king of all exchange whether CEX or DEX
2.Coinbase: I have also considered Coinbase as a potential exchange doing great job especially in the USA
3. Kracken, a reputable exchange with high security, has great future.
4.Kucoin, team are doing wonderfully well and may likely overtake the others to the top position in near future.
5.Huobi Global, excellent exchange with good features, and great daily volumes.