I personally would prefer Ethereum, because
1. Ethereum is more experienced than BNB
2. more people trust to invest in Ethereum than BNB
3. Ethereum price increase is higher than BNB
4. more projects use Ethereum than BNB
5. Ethereum ranks 2nd on coinmarketcap while BNB ranks 4th on coinmarketcap
6. many people agree that Ethereum is the king of Altcoin

that's my reason why I prefer Ethereum rather than BNB at this time.