whats the best currency to invest?

Agreed ^

a few other noteworthy coins to take a look at would be ethereum, litecoin and stellar. All of these coins are available on coinbase which is the best cryptocurrency platform out there. This is just my option though, don't take my word for it as well as all of these other people telling you which coins are the best. I advise you do your homework and invest into a project in which the company actually cares about their product and is passionate about succeeding it. Good luck brethren!