ETH is a must in this case. Probably exchange tokens can be in this portfolio as well - BNB, KuCoin etc. If crypto will develop, their prices will be higher than average.
Token BNB is a very good choice, I also invest in a BNB for the past 4 months. I fully support your choice.
To be honest, I really liked the Binance trading platform, but so far I had nothing with their coin. I think if this project is the most ranking of all possible, then their bnb coins have very great prospects.