This very week I switched to a new ISP. Having a connection of your own for the first time in your life makes a huge difference in terms of how you handle your own ports to play nicely with your software.
One of the things that I had always wanted to do was installing a torrent client which could run unattended. I have a lot of experience with mldonkey, which is a client for several networks, bittorrent among them. However, I was looking for a lighter client for my raspberry pi. I tried several clients: rtorrent, ctorrent, and I finally settled for transmission, or more accurately transmission-cli.
Many, or most clients, have both a GUI and a CLI, some of them have a web interface which is great for managing your downloads from a remote location. But I somehow prefer logging into the machine using ssh, opening a multiplexer instance (usually screen) and fire up the bittorrent client. This is damn simple for all of us who spend most of our free time logged into remote machines, for work or play.
Using transmission-cli is easy peasy:
$ transmission cli *.torrent
Update 11-10-2015: A friend of mine suggested trying transmission-daemon and its web interface. I did. It is great, even though it needs a little tweaking since it uses a different user by default (debian-transmission) and you have to give that user write permissions to the directory you want to store your files.
Update 24-11-2015: Even though I use transmission-daemon and transmission-cli on my raspi. I exclusively use rtorrent in my laptops and servers. rtorrent is a really powerful and handy bittorrent client.