qTorrent is a lightweight, but feature rich BitTorrent client for Linux. The latest release includes Audio/Video File previewing.
Other features are:
qBitTorrent is based on the Libtorrent library and is written in C++. Here is a screenshot.
You can download qBitTorrent over here. qBitTorrent is available in more than 20 languages, and is developed by Christophe Dumez, a French Computer Science student.