i've been using various p2p software.
starting with Kazaa, Ares Edonkey, and Limewire.
now only stick with Kazaa and Limewire.
Edonkey sucks full of spyware and viruses.
I have used many of them like uTorrent, BitCommet, Azurus, eMule, LimeWire but i like Bitcommet the most. Its easy to use and fast among all of them which i mentioned.