Ripple is one of the altcoin with huge market capitalization, it has the advantage that it is used in many banks in the transaction. However, I think you should be careful with Ripple. Ripple is managed by the company, you will not know when the ripple will die. My favorite altcoin is Ethereum and Monero. Ethereum is very stable. Investing in Ethereum promises to bring a lot of profit for us in the future. Monero is private, every transaction with Monero is completely anonymous, no one can find out the user information.