That coin flatlined for years. What happened and how do you know it won't happen again?
OP: It depends if you want safe or risky. Safe: ETH, NEO, maybe LTC. Risky: Buy whatever is getting shilled the hardest. Right now that's VEN.
for a good Altcoin for investment would be great for using Ethereum. because with Ethereum is increasingly able to bring Ethereum into a coin that is very reliable for the future. in addition to investing in Ethereum will make a pretty good profit going forward and bring it into a high enough value.