Based on various factors there might be different classification on the best cryptocurrency for the year 2019. For me bitcoin is always the best and that mentioned in the list provided with a gradual growth without much large scale dip in the price. From my experience my portfolio is entirely different from these assets holding and 2019 is that good as I expected.
Price of all these coins are tightly coupled with bitcoin. Its now getting clear with each passing day that its very hard for altcoins to have there own upward run. Thats why people are restricting them to bitcoin only or may be few strong altcoins like Eth, LTC. I have also shifted major portion of my portfolio to bitcoin.