Because of the crazy market manipulation, I recommend you to always understand how a cryptocurrency works and what problems it solves. Only that way you'll be sure for your decisions. Did you know, for example, that XRP is being fully control by an entity and they can inflate it whenever they want? Did you also know that the majority of ETH are premined and it's being very volatile due to the Vitalik's influence?

Monero has a great potential IMO. It's anonymous and completely decentralized.

I think it's pretty obvious that if you invest in one of those with the highest market cap, excluding Dogecoin that was recently pumped hard, and wait for five years, you'll have a profit. But which of them will bring you the biggest profit? No one knows. I could guess Bitcoin.