Please write a single answer per comment to clearly see the most popular tools. Vote on the ones you like.
There were too many options in this post and I want to see what are the really interesting ones.
To complement this post:
What file-sharing and media organizing software do you wish that existed?
deleted by creator
Musicbrainz Picard for fetching music metadata and standardizing file naming schemes.
digikam for image and video collection management and viewing (also does duplicate detection)
Tixati is an alternative torrenting program that I switched to from QBitorrent.
mldonkey cross-platform multi-network p2p daemon
beets music library management and tagging for geeks
rtorrent great to download torrents especially on a server.
Sonarr for a PVR for Usenet and BitTorrent users that can monitor multiple RSS feeds for new episodes of your favorite shows.
Transmission for a fast, easy, and free multi-platform BitTorrent client.
ffmpeg the Swiss army knife for everything video and audio.
Radarr for an independent fork of Sonarr reworked for automatically downloading movies via Usenet and BitTorrent.
Navidrome for a self-hosted music server and streamer compatible with Subsonic/Airsonic clients.
Prowlarr for a meta-indexer that integrates with other applications like Sonarr, Radarr, and Lidarr.
aria2 for downloading files.
