The answer is always Monero/XMR, other "privacy" coins where their users isn't forced to use privacy features or the transaction details (sender, receiver, amount) can be seen by anyone isn't real privacy coins.
But, if you use coins where user isn't forced to use privacy features, but both sender and receiver use privacy features, i guess Zcash, Zclassic & DASH are fine.
I completely agree on this