tried out a lot of different clients....but found utorrent to be the best...no installation problems, no update problems, just one single clickable exe....
I like both Azureus and UTorrent , but using Utorrent currently coz My hostel PC is so Turtlish that if I dare install Azureus , BasT**D gonna throw up on me.
Currently using BitComet..n although Utorrent is good, it sometimes eats up all the available bandwidth..n then browsing (with it running in the background) really becomes a pain.... never faced this with bitcomet till now..