The best coin could be the one who will achieve scalability ? Then you have to take into considerations realistic expectations against fairytale hypothesis relying on unproven doubts.
Mere speculation. Certainly not the best coin, with lots of drawbacks, but I think that a coin like Dash which has a complete roadmap on improving its hardware infrastructure to achieve expansion, if only aiming at 50 million users, is closer to a "to the moon" status, just for anticipating some consistent work schedule and matching it to the core project (here, taking place as a payment system)
In the end, any coherent coin which will find the means to pierce through, besides dreaming big !