I dont think bitcoin as a best investment because this is so volatile and risky but all i can say that bitcoin is a good investment too but you have to control you investments that you can afford to lose only.
but i am too much sure about the bitcoin investment and can say that there is no doubt about that bitcoin is the best investment in current time. actually the income that we can get from bitcoin invest, i do not think that it is possible from any other kind of investment, therefore i think that in current time bitcoin can be called as the best investment.