Rockstor and YUNOHOST are both fun pieces of software for home severs.
Nextcloud, TTRSS, Wallabag and Plex are all very useful.
Wire can now be self hosted and is shaping up to be a pretty nice alternatives to other chat software.
Kaldi, which is an open source speach recognition engine is neat. There is an ongoing effort to have it run with Mycroft so anyone can self host an AI assistant.