client for the Bittorrent peer-to-peer file

uTorrent. The best.

Transmission

I use a combination of uTorrent, Bittorrent, and qBittorrent :)

using utorrent here

utorrent

at windows, i use uTorrent. fast, lightweight and you can use it at any tracker without hesitation.
at linux, i use Deluge, right now -that's because at pretome, you can't use qBittorrent- but i love qBittorrent. but the biggest let down of qBittorrent, it does not hold your stats -even this is not a big deal.
i tried Transmission -sometimes changes your preferences, like ports etc.-, Vuze, KTorrent as well. but Deluge and qBittorrent are the best ones imho.
also qBittorent has a very good search option -with nonofficial plugins you can add some other sites too- but, rss system sometimes goes crazy.

i use utorrent but i used somedays qBitorrent and i liker very quick and soft

I have been using uTorrent for about 8 years now. No problem whatsoever with it. I cant bring myself to change to another torrent client. On the linux side I mainly use rTorrent.

Utorrent only

its lite ,does not bug memory
cool , simple

qBittorrent, uTorrent sucks balls now :(