Please recommend me 1 best Altcoin to buy

[nebiki]

I would suggest below some of the small coins. Each of these coins have working or beta products and current price is too low compared what they are bringing : STRAT, XRP, LISK, NEO, QTUM, OMG.

it is very true and the coin is well suited to be used as a trade and good chisel also if to invest, because the price of the coin is still low. so if I think if you want to invest the best coin is the coin ethereum. because the coin is very profitable if used as an investment in the long and short

[moshk555]

I have a plan to invest in no singular altcoin  when the market start is recovery period but if you invest in one-coin choose the one with the lowest market cap which has the largest potential to grow  and that is litecoin

[Zitudent]

Since you already bought and keep Ethereum, Litecoin, Waves and Neo, then I can recommend Iota and Cardano to your crypto portfolio. In the future, these tokens have a good chance of great growth.

Further addition could be BCH.