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.
Yes until now bitcoin is most used, most invest from users because of the good it has to the users. I save bitcoin for the long term for the profit that we can get from patiently holding in our wallet. Price up and down but it can bounce to rise any moment.