The are 3 major categories of cryptocoins. Bitcoin - Altcoins - Stablecoins. 

If you want you money back exact at the same price as before but you afraid to have euro or dollar or something else then invest at Stablecoins . One of them is dai and the value of 1 dai = 1 Dollar

If you want to invest at something solid , that has duration over 10 years and you are dreamful person then invest at bitcoin. It is over 10years so there is no worry to crack and loose your money and in the future it can gain more value.

If you are risky guy invest at Altcoins (alternative coins). They are more rockets coins. From them the most solid is Ethereum and litecoin. One good investment it probably could be stellar xlm.