NEM seems to have the most complete and useful technology stack built right into its wallet.
It has a notary service that's very robust (https://blog.nem.io/apostille/), an ability to buy XEM through Changelly (although the rates are horrible), a messaging service to accompany each transaction, low transaction fee, namespaces to assign labels to addresses, smart contracts, and a multi-signature and multi-user account.
It's very exciting stuff and I encourage you to look deeper into it.