A possible scenario is this: Cardano, PRiVCY, EOS, Stellar and the like. It is only if these projects will develop its platform and on.
In this year 2018 I think the best altcoin is ethereum because this is the one who fluctuated in its prices ,this coin is more demand for investors because the amount we invest or buy in such coin has a good returned of profit.
I agree with you. This year Ethereum is a star. It holds a firm second place after Bitcoin which is saying something about the capabilities of this altcoin.