I have extensive dealings with Bit Torrent clients. Among those I've used I found BitComet to be the most to my liking, however it seems there are some issues with it that have caused certain Torrent sites to prevent its use. Therefore in its absence I went to uTorrent.
After having used uTorrent for a good long while now I can say with certainty that it is the most effective, non-intrusive, likable program. I used Azureus for awhile but it was pointless. Way, way to many options, slow and clumsy, it basically stunk in my opinion. So here is my suggestion:
1. BitComet
2. uTorrent
3. Bit Tornado (I've found it was somewhat slow, but also it acted odd at times)
4. Bit Torrent (original client)
Yea yea, the original client isn't spiffy but it'll get the job done, besides that how can anyone even be certain it's not as fast as the others out there, anyone here tried
In any event Azureus is a no, no.
Also don't download music, buy it using iTunes like I am. It's easier, you get songs that were all encoded using the same bitrate, and you are assured they'll be no skips.
So in effect iTunes is good for music, I own 250 songs now
Torrents are good for testing out software you may wanna buy but which has no trial version available.
Also Torrents are good if you wanna download Anime from Japan that otherwise would never get here, fans subtitle it and then upload it. Although this is boring to me now because I hate to read!