As per my suggestion You can go with Ethereum, Monero, Neo, Dash, Waves, Stratis and Zcash all these coins are good for long term holding and already established in this crypto market. All those coins have a background and they have potential to grow.
I am confident in ethereum and bitcoin for long term hold. this two coins are very popular and its now slowly growing in the market, its popularity is gaining more and more investors in this crypto world.