You can always see the price history of two, but BCH is a bitcoin fork and I don't see a fork would be successful in the long run.
Bitcoin cash launched in 2027 n Ethereum are staying online since 2015, so Ethereum has more users and it is widely spread than Bitcoin cash. so in this case I will go for ETH.
Block confirmation time for Bitcoin cash is approx 10 minutes where Block confirmation time for Ethereum is approx 15 seconds. so Ethereum is faster than Bitcoin cash.
Moreover, Ethereum's previous history is very good and it is popular for smart contracts so that Its value is always increasing. Ethereum is much more trustworthy than Bitcoin Cash.