µTorrent 3.4.1.30783 + Portable | 1.8/3.1 Mb
µTorrent is one of the most popular BitTorrent clients, with plenty of features such as bandwidth prioritization, RSS auto-downloading, scheduling and Mainline DHT (which is compatible with BitComet, another well-known BitTorrent client), Protocol Encryption joint specification (used also by Azureus, BitComet) and peer exchange.