The top 3 altcoin that I will invest now is Ethereum, Cardano and NEO. Ethereum is the queen of all altcoin, it has the perfect power, most of the ICO projects use the ERC20 platform of Ethereum. Cardano has a professional development team, it has good scalability, I believe in the next few years Cardano will become one of the best altcoins. NEO was born in China, it has technology and development plan quite similar to Ethereum so many people call NEO is Ethereum of China. NEO is worth the investment.