Some people here are making their choice based on which of these coins has been around for a long time, has the largest market cap and the market price. Well they might be right because ETH is the second best cryptocurrency there is. But talking of which one of these two is going to be profitable in this year (2019), I think the answer is Binance Coin and my reason for saying that can be seen on walletinvetsor.com, if you compare the both of them on that site based on their performance you will see that ETH is just a runner up while BNB takes the win. But it's still up to you, and there is nothing wrong if you invest in the both of them, that would even be the best thing to do.