I think for most of the public coins, aside from those that will enable novel games and perform social media functions, their time is short. XRP like it or not will rule them all including the mighty prince LTC, and king BTC. XRP is the fastest most efficient and cost saving tech out there. XRP is about to move in like Walmart and send many alts packing. even IOT which Ripple calls "the internet of value" be dominated. Smart contracts..Check..Ripple has that covered too since 2012.
Private crypto like Intensecoin
http://intensecoin.com is the future beginning in 2018.