You're right; it is hard to choose. On one hand, anyone who actually has had to move bitocoin recently knows its slow and painfully expensive, especially for small quantities. Bitcoin cash on the other hand feels modern and quick. On the other hand whenever I have bet against Bitcoin, I've always got hurt. It seems that the power the core brand is to strong.
I like ETH long term as well for it's incredible smart contract utility and quick blocktimes. Though I don't think it'll be the same kind of store of value that BTC or BCH is due to inflation, it'll definitely go further then it is now. Good long term hold no doubt.