There is many altcoin still has more potential and value worth to buy. But, you need to choose the highest traded volume crypto. I would like to suggest you only IOTA, BNT and Bitcoinz for the investment because I personally have this in my portfolio.
for IOTA I support because it's a good project, but for BNT and BitcoinZ I still haven't analyzed it,
maybe later I will review it before trying to buy it, thank you, and try to add your portfolio, I also have one interesting coin, namely Credit