Bitcoin of course. Check out this website for more info  https://thejingstock.com/

Bitcoin is the future. You can see that in the last few years the number of investors who turned to bitcoin increased dramatically. Also, the number of both giant companies like Sfox and smaller brokers like this one https://thejingstock.com/  keep entering the market every day which means there is a demand. Imo there is a bright future for crypto in the next 5-10 years.