I think Bitcoin is still the best to hold for a long term because bitcoin is the most popular coin all over the world and most use coin than any altcoins. Bitcoin has been the leader of all crypto currencies since its creation even there are many altcoins that was introduced in the market. Bitcoin has already proved that it can survive for many years and can continue to increase in the future.
If we will based on the stories of the people who'd been rich by just holding it then we can definitely say that bitcoin is worth holding for, even 50 cents who happened to forgot his btc gains alot now as well other young holders of it before.