It is always better to diversify your investment portfoilio. For altcoins to invest in, I suggest you research and invest in the altcoins you think it is promising and bring you good returns.

The one who caught my eye is Propthereum.io. They are an upcoming asset backed coin. If you are interested in investing in ICOs, i suggest you check them out. They are expecting a 1566% coin appreciation in a short period of time.