Ofc the best is Bitcoins. But there are some decent alt projects as well. The altcoin I think is pretty cool is Stellar. It's really fast and cheap. Think of it, IBM creates a platform for international transactions using Stellar protocol. I wasn't keeping Stellar on my radar, considering it just a ripple fork. Yet I've read Stellar review on undervalued.top and picked up Stellar for my portfolio. Things are gonna be great, or at least it seems like that.