KuCoin · 
KuCoin is one of the largest and best known of the cryptocurrency exchanges, as it's been serving its clients and providing excellent service since launching. KuCoin is often considered to be the best crypto exchange for altcoin hunters thanks to its massive selection of tradeable assets. In addition to that, it also sports very low fees, a platform interface that's suitable for pros and beginners, bank-level security, and a number of other services that can be difficult to find elsewhere.