I use uTorrent, What.cd, Waffles.fm, STMusic.org, and maybe, just maybe, if none of those have what I need then I'll look on Mininova or TPB. There was a 26-CD Dylan bootleg set that was on TPB that none of the private trackers had. So it happens sometimes.
But uTorrent seems to kick *** as far as torrent clients go...