although both are currently the best coins, I think ethereum and neo will still continue to be debated and maybe ethereum will continue to be one of the better coins than neo. so this is a choice and must be determined if ethereum is the best choice for the next few years 
As for me eth can gain much bigger value in five years from now, because of its growing market contracts. Many crypto coins has a good standing on trading launches, that's why the potential growth will really have to increase from time to time. Every year it chances to much higher value that could attract more buyers to trade.