uTorrent

Most of the features present in other BitTorrent clients are present in µTorrent, including bandwidth prioritization, scheduling, RSS auto-downloading and Mainline DHT (compatible with BitComet). Additionally, µTorrent supports the Protocol Encryption joint specification (compatible with Azureus 2.4.0.0 and above, BitComet 0.63 and above) and peer exchange.

The developer puts in a lot of time working on features and making things more user-friendly. Releases only come out when they're ready, with no schedule pressures, so the few bugs that appear are quickly addressed and fixed.

Links: homepage - download