Currently me and my friend are using a self-hosted server with Matrix, and Sable as a client.

Sable is the only one with Discord-like functions out of all the clients I've tried, all the others falling very short.

Besides that there is Fluxer, which is far more feature complete than any Matrix client. It has some key features holding it back, though, which are no Federation yet, and no E2E encryption yet. But otherwise setting up your own fully functional server is incredibly easily.