I choose bnb for myself, as binance is constantly promoting it, introducing different types of earnings on the exchange, in which bnb is always required. And also, binance burns coins every quarter, thereby the supply decreases, and the demand increases.
Many time Binance have good promotion with BNB but I think still worth for investing with ethereum, you can see today when ethereum back to lower price last day above $498 and now ethereum have reach above $556 and have potential back again above $600, just waiting when moment for bitcoin up ethereum will up too. Better hold and invest with eth I think than you choose BNB because BNB very slowly raise to higher price and never get anything chance cross above $100 although many time burning because Binance team is not trusted and they will sell first when have moment for burning.