My vote would be for a cryptocurrency that has the promise of value beyond a means of speculating. Ethereum has functionality with smart contracts, Iota could be a huge player in the IoT space, FileCoin for distributed storage, GridPlus as a distributed energy exchange. No way am I picking winners here but there's a Mark Twain saying, "“During the gold rush its a good time to be in the pick and shovel business”.

That certainly applies now.