Ethereum and Stellar remains most promising among blockchain projects. But I have more keen interest in younger coins such as Morpheus Labs and Vite. Both with an incredibly low market capitalization of under 10m usd with the potential to do X10 easily
Ethereum and Monero where my pick but for the younger coins i was thinking about GRIN. GRIN still got enough room to get higher on the rankings.
I think you really called one of the most promising coins in which you definitely need to invest. But I want to mention another coin Tron, whose platform is becoming very popular for many gambling. In addition, I see that this platform is beginning to outpace competitors such as Neo and EOS.