The list of the best altcoins must begin with Ethereum, which is the second most valuable cryptocurrency after Bitcoin.Litecoin is also just a digital currency but with improvements. NEO, like Ethereum, is a platform designed for developing Decentralized applications (Dapps), Smart contracts and ICOs. Cardano not only offers a platform for Dapps and smart contracts, but also offers many technological improvements over Ethereum and other blockchains.