It depends on how much you want to earn and how much you are willing to sell, I see bitcoin, along with eth and ripp the most stable coins on the market, these can leave you high profits if the hodleas for a long time, however if you want to bet and try to get rich in a week you can try to invest in an ICO that promises a lot, so you can make x100 in a month.
Certainly splitting money into places is better than focusing on buying bitcoins or investing ICOs, both of which are great things and will make our money grow well and of course safer.