I think if we talk about the best altcoin by 2018 this of course it is ethereum,
because ethereum has a bright and promising future,
so I think so ethereum does not need to be doubted anymore
yes, that is a fact I see the development of Ethereum is better than other ALtcoin and now it is widely used by ICO project, the average of all projects using Ethereum so I believe the future of ETH is very bright.