Bitcoin. Bitcoin is not the core of the currency itself, but the bitcoin agreement. Bitcoin ecosystem contains many possibilities, which is the biggest difference between gold and it, because the former belongs to the future.
It's actually a though question.. Bitcoin is good for now because we are using the technology and we have access to it, and Bitcoin cannot be confiscated by governments like gold was in many countries worldwide.. But if one of the Internet structure fails, Bitcoin would be over. I was taught to split my risks so if one fails, I will still have the others. Sure, the investment is way smaller in each then but I would not have to risk losing all at once.