Obviously, that will always be Bitcoin. People have no interest in any other crypto currency aside from speculation purposes. We have seen enough coins pop up, and none of them have made anything change in that regard, not even Ethereum. Ethereum is only hyped and pumped due to its connection to ICO's, but now ICO's are slowly but surely facing more and more governmental resistance, Ethereum's main source of growth will be cut off. It's maybe not much of a good thing to see happen if you're an Ethereum fan boy, but it is what it is....