Definitely BTC or BCH in my opinion. In altcoin, ETH, NEO or Monero also the good choice.
- The high fees and slow transaction times of the original bitcoin are a deliberate, but somewhat unfortunate, design choice. The idea is that bitcoin could be digital gold.
- For another one that is Bitcoin Cash was deliberately split away from bitcoin by a team who thought high fees and slow transactions would eventually destroy bitcoin. It was deliberately designed to essentially be bitcoin, except easy to send, receive and transact with. Hence the cash part of its name. It was designed to be the spending money next to bitcoins gold.