Tools like uTorrent continues to be positively received by users all around the world. The additional ads on uTorrent will bother some people, but most people will just be happy to have a product...
Free. Windows. If you're looking for a good BitTorrent client, try uTorrent. It has what other BitTorrent clients have, such as scheduling, bandwidth management, and Mainline DHT, plus extras like a unique protocol that detects and corrects for heavy traffic.