The answer is definitely Bitcoin, but if you are looking for alternative crypto money to invest outside of Bitcoin, the advice I can give you is to choose the top 20 or even the top 10 options if possible. I also recommend that you make an option that is centralized and devastated for its investors such as Ripple (XRP) out of the list when making a choice in this ranking. On the other hand, you should also take care that the crypto money you prefer will be stored with a reliable wallet when you create your investment basket.