Tour Magazin did a big test on chains some time ago. http://www.tour-magazin.de/services/...11/page45.html

I run a 105 5701 currently and it's one of the most smooth shifting chains i've had.
Earlier i used to run Dura Ace chains and KMC, but honestly i don't see a reason for paying that much for a chain agan. The 105 does the trick, and very well too.

Edit: Link already posted. But there's some good data in there.