With the currenct price of XRP ripple coin, my idea on it is that it is very good investment with that price and it can pump its price for a long term investment and in the long run it can increase its price gradually since it is now a potential coin in the market.
That's the keyword there, pump, the last time it was really pump hard was like two years ago. So if you are willing to wait for about a year, then we can see it pump again. However, I'm not into the alt coin markets but I would say that ETH or LTC (specially with the halving coming in months), are the best altcoins for me.