It is difficult to speculate now, because everything may change the way we don't even expect. At least I know for sure that Bitcoin is here to stay for a long time. As for the altcoins, they should solve some real time issues and have connections to real time businesses and be integrated in these businesses. I can give example of "KIN" coin. The team is building the inftrastructure around this coin and try to integrate it in their chat called "KIK".
The price is below ICO now. Could be potentially interesting for long-term hold.