Both of the coins have a long history and have a huge potential for further development in the cryptocurrency market. Nevertheless, I have voted for BNB, and there're a few reasons for this.

Firstly, the BNB coin now acts like BTC on Binance with a limited sphere of influence. Whatever you do on Binance - trading, participating in IEO, inviting referrals - everything is tied to BNB, which is the token of the largest exchange. BNB is second to none when it comes to debating and comparison of BNB/BTC/ETH . BNB's token economy was well developed and is proped by ICO model crash in 2018 which is related, first and foremost, to ETH and its smart-contracts technology. ICO, as a phenomenon, has gone away almost completely.

Secondly, the trend of token/coin offerings currently belongs to big-boy-exchanges like Binance rather than to smart-contract platforms that lost investors' trust.

And, finally, BNB used to be a brainchild of Ethereum platform, now - it has its native blockchain.

BNB has become a store of value, an instrument of investments alike to equities in the stock market.