I just posted asking the same question. That is the million dollar question lol I think BTC is the AOL in this industry and the GOOGLE coin is around the corner. It is really difficult to pick and choose between all the new coins out. There are a few decentralized coins that I watch and wonder if the will shoot to the moon one of these days. I hear and read a lot about XMR, I notice the people tend to hodl for XMR. I really believe in their roadmap and the founders behind it.Also ZCASH is another security coin with some potential. As to how quick and how high the fees will get say if the mass public was to adopt it, is another question. The next coin will definitely have to have extremely high speeds with vast amount of room to grow. The next coin will have to be able to conduct everyday transactions for next to nothing and still have the security as BTC has. There are a lot of factors to make the perfect coin and it seems to be very difficult to have all the components in one coin, but when one does have everything; it will become the "GOOGLE" coin. Keeping an eye out for the one that has all the trade marks of a perfect coin.