I read a review of loads of different ones which were product tested by members of the public (I was part of the panel but not for eye creams unfortunately!)
The one that came out top for reducing dark circles was Korres vitamin E cream. It's not cheap but all but one of the product testers said they saw a difference in the appearance of their dark circles.
Incidently, in case someone suggests haemmoroid cream, this is for bags and loose skin under the eyes, not dark circles!