The first best coin to rock this year and which is better all the time is Bitcoin, thus that's the best coin i can rock this year without fears. Also I won't say Bitcoin is slowly growing up because it is still highly valued and no coin has even gotten close to it. Another I can look at is Ethereum because it has shown and proven till date to be stronger than most altcoins; having in mind its upgrade is coming soon. Binance coin, Xlm and ADA also made my list but not in a larger portion when compared to Bitcoin and Ethereum.