I think for me for today, it would be HIVE token. If I was given it I would use it to improve the retention on Hive Block Chain. Even if that meant selling out and buying witnesses and paying developers to fix the broken witness retention/selection system, and the down vote system. I think getting those two things fixed and actually usable in a decentralized state would put HIVE token increase over the three year span greater than any growth of Bitcoin percentage.
There are very few investments one can actually actively improve return on investment chances. Real estate used to be one, but for a three year growth cycle it is pretty risky unless one get lucky on location choice and price growth potential.