For the purpose of P2P digital Cash I'm betting on Dash, NEM, PIVX mainly. There are other good products like Verge or ZENcash and Hcash. I've actually gone as far as to say BTC will worth $500 by 2020. Why?
Cryptos aren't real things. They are just software, computer codes, math. Their worth is in the functionality. A crypto needs to excel at
- Utility
- Usability
- Scalabiliy
Take Dash for an example. They resolved the block size issue in a matter of hours. They are scaling to VISA level Tx volume with fees worth cents and transactions that take 1.3 seconds. You can even decide to pay 10 times lower fees if you are willing to wait 2.5 mins. When transferring to an exchange they ask for 6 confirmations and it has always been ~15mins for me.
Just visit the site and behold the awesomeness.NEM support smart contracts. Has multi-signature support. It has tons of use cases: https://nem.io/enterprise/use-cases/
Amazing partnerships: https://nem.io/enterprise/partner-companies/
Then there is PIVX which is just PoS Dash with few changes and Zerocoin privacy instead of trustless mixing. Feel free to check them.
My favorite is Dash and their community is just heavenly angels compared to some fights I've seen in the crypto-space: https://steemit.com/@vimukthi/lessons-from-dash-community-vs-pivx-how-to-act-like-the-adult-in-the-room-and-stop-the-pointless-hostility-to-embrace-the