Deluge

Very good torrent client. Don't forget to download the GTK2 themes package if you're on Windows (gtk2-themes-2009-09-07-ash.exe) because the default look is really ugly (not suprising though).

Strong points :

• Good community

• Accepts plugins to extend possibilities (you can code your own plugin)

• Able to add multiple torrents at the same time and apply the same options to every torrent.

• Auto label torrents by tracker when you add them

• Mass relocate folders and force recheck (useful if you have one folder per label and you want to force recheck all the torrents of said label)

• save folders depending on labels like µTorrent "append the torrent label", but with custom speed limitation per label

Downsides :

• Coded using Python and GTK+ so the UI is slower on Windows compared to qBittorent for example (Qt framework) although it's not dramatic at all, i've seen worse.

• I have a superior tracker error rate compared to other clients. Sometimes these errors stop your seeding torrents. Only client to do that so far.

EDIT : nope, after investigation only one tracker is causing problems and i could see the same problems in µTorrent. Not all the torrent clients report errors like Deluge, that's why i thought i had more problems.

All in all, since µTorrent starts to be bloated with ads thanks to Bittorrent company and since the original Dev doesn't take part in the development anymore from what i read, i'll keep Deluge as my main client.

You can also go the qBittorrent way if you want a simpler client. It's very close to µTorrent in terms of features but keep in mind that some private trackers don't like qBittorrent (banned in some places).

27/08/2012 EDIT : qBittorrent is now whitelisted on every tracker as far as i know.

[Edited by TDL, August 27]

After all the "traditional" clients like BitTorrent, µTorrent, and Vuze/Azureus have become so bloated and pretty much unusable, with horribly bad UX, over the past couple of years, it was finally time to get rid of my laziness and find a replacement. I have tried a few options, and quickly settled on Deluge and qBittorrent. There really isn't a bad word I can say about either.

Deluge is a very light-weight client with a well thought-out client and server separation. Which, however, you don't have to worry about if you're a regular user on a regular desktop computer. Just install and run, the daemon will be started in the background and the user interface will show up. Unless you switch to "thin client mode" and configure the server separately, it handles like any other, monolithic BitTorrent client.

And this principle works all throughout Deluge. Everything is really simple, easily understandable, in a clean and tidy user interface. If you need more powerful features, they're just a hop to the settings screen away. What's also nice is that many useful features which, however, not everybody will want to use, such as notifications or torrent labels/categories, are implemented as plug-ins that can be switched on and off at will.

I had Deluge set up on my Windows machine in no time, configured it to my liking within two minutes, and everything works as it's supposed to. It gives me a generally good impression, it seems like the people working on it know what they're doing, write quality code, and care about user needs. From the documentation and forums, they and the community also seem like a generally friendly bunch, and not an elitist club, which is always something that puts me off of some other open-source projects.

Important detail: Deluge is also a widely accepted client on private trackers, I haven't found any site that would disallow its use.

Deluge has quickly become my main BitTorrent client, and I can recommend it to anyone. Why Deluge over qBittorrent? Coincidence, really. I traditionally split my torrenting between two clients for different use cases. Deluge got assigned the task of main work horse, and I haven't regretted the decision. But you really can't go wrong with either of those two clients.

One of the oldest clients and completely free, no annoying ads or anything. Works fast, easy to set up.

Pros:

• Runs smoothly on Linux and easy to set up and configure.
• Use it quite frequently and has worked well, no issues regarding its functionality.
• NO ads.

Cons:

• Careful when removing torrent, had times where I removed torrent with data by accident.

No ads.
Not a bloated resource hogging pile of crap like Vuze.
Quick and easy.

People have said that it's easy to accidentally delete your download, but I feel that it gives plenty of warning.