qBittorrent is probably the most actively developed Linux Bittorrent client, with new versions being released constantly fixing lots of bugs but also adding nice features to make you forget 

qBittorrent is a multi-platform lightweight but fully featured BitTorrent client, very similar to uTorrent.

It features a µTorrent-like User Interface, torrent labels, WebUI, µTorrent spoofing to bypass private trackers whitelisting, advanced RSS support with download filters and many other really nice features.

qBittorrent is a multi-platform lightweight but fully featured BitTorrent client. It's authors claim it's the closest open source (GNU GPL v2 license) equivalent to µTorrent.

qBittorrent is a Bittorrent client using C++ / libtorrent and a Qt4 Graphical User Interface. It aims to be a good alternative to other bittorrent clients. It has more and more features such as an integrated search engine, UPnP, encryption, PeX, a torrent creation tool .