you can choose what coins/token will be popular in 2019.
include the reason coin/token can be popular.
One coin in which I have my sights on is Stellar Lumens. During the past few months, its exchange rate has gone up, contrary to the general mood in the market. Also a number of ICOs are now using Stellar as a platform.
Don't forget latest news that Blockchain Wallet will add stellar in their list. It means Stellar is already looked by big online wallet service and it can be good for Stellar/Lumens itself in future.