KTorrent is definitely the most full-featured BitTorrent client for KDE. It is complete by any means and highly configurable, offering, among many other: search capabilities (with the results opened in a new tab and the possibility to add custom search sites), the possibility to create torrent files, pause/resume torrent downloading, system tray integration, detailed information about the torrents it downloads, a queue manager, various useful plugins. KTorrent has come to be probably the most complete BitTorrent client out there, being also fast and having an option to use low CPU resources.