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.
yes, I agree with you, what you say is true, Ethereum is the best Altcoin, I see the development of Ethereum is better than other ALtcoin and now average ICO project based on Ethereum so I firmly believe the future of ETH is very bright.