My favorite private coin right now is XSPEC. Its extremely undervalued right now. Max coin supply near BTC/MONERO/LTC at 20M. It runs entirely on the tor network with all traffic staying inside the tor network. They use obfuscation so you ISP's cant tell that you are connecting to TOR. It also has a unique way of anonymizing the transactions. PoS so its energy efficient and doesn't rely on miners to support the entire network. It is also censorship proof and will work in countries that block TOR like china. These are also features that are already implemented. Theres also a built in encrypted chat feature too which I hope they flesh out more in the future.