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?
Tixati is an alternative torrenting program that I switched to from QBitorrent.
Why use Tixati over qBittorrent?