The most ethical #smartphone is one you keep for as long as possible.
However, if you have to buy a new one, there are a couple of models you might consider:
@Fairphone - Modular #phones made with a more ethical supply chain and greater environmental considerations. Available now:
@Purism - The Purism Librem 5 runs proper Linux (not Android) and is designed to be as private and open source as possible. Due out in April 2019: