Zippo Blu Lighter, Vargo Triad Alcohol Stove (both completely unreliable) and a Leatherman Core (tips of the needle nose pliers pinged off). The LM core has been relegated to fishing tackle duties after filing down the pliers. The Leatherman Skeletool CX was a bit of a let down as well considering the cost (I dislike the dangerous serrated blade and limited tools).

Otherwise there hasn't been many other products that I have found to be inferior except for an expensive SIGG Thermo Ring Line Bottle, which was basically useless as a vacuum flask.

Edit

I forgot about the Buck Camp Axe - There are some UK retailers selling this mediocre axe for an unbelievable $85, when you can get a Gransfors Bruks for the same price.