I'm using 2.2.1, though I'd be happy with 2.0.4 which was also great for me. Another member summed it up nicely: Stable; has never crashed No disk I/O and caching issues No ads No social features No streaming features No multimedia features No anti-virus integration Clean and fast UI Seriously, µtorrent became the king because it was tiny, fast, any computer could run it, and it had no stupid bulk. Everything since 2.2.1 has forked in an entirely different and highly annoying direction. It used to be that clients would get banned from different trackers when they got old. Fortunately, everyone seems to realize how dreadful the 3.x versions are so client-banning has virtually disappeared with the realization that a lot of people have no intentions of upgrading. As long as that remains the case, I'll be using 2.2.1 for years to come. Who wants ads, streaming, multimedia, and social features in a content downloading program??