Keep in mind not all "privacy coins" are private. Some claim to be private because they have a privacy mode or just simply use IP obfuscation.
All monero transactions are private. The sender, reciever and amount are hidden. This is a true privacy coin because of these three features.
ZCash privacy is opt in
Dash I do not consider to be a privacy coin but is called a privacy coin since it has a privacy send mode.
There is Firo which I have not used much but I believe its privacy is opt in
Zano is a privacy coin that looks promising.