Dash, you can have 1000 of those and running a master node, which kind of paying you some interest.
Agree. making
DASH node(it cost ~9000$ now) is the best choice for passive income, and the development team and community has repeatedly demonstrated this. also i recommend you to stay away from cryptocurrencies with an unlimited supply of coins.
Agree too, you may get sway running Master node in Pi 2.