The most reliable cryptocurrency exchanges are Coinbase, Binance, Kraken, BitMEX, Cex.io, and Gemini. All of these exchanges have excellent security measures in place to protect against hackers and other malicious actors, as well as reliable customer support teams and an array of different payment methods. They also operate under stringent anti-money laundering (AML) and know your customer (KYC) regulations, making them some of the most secure exchanges in the world.