I'm a sucker for infomercials! I don't remember the proper names for everything, but here goes.
Oxiclean - didn't work for me. On anything.
Nads - love it, the only 'waxing' system I used that pulled out every one of my super fine leg hairs.
George Foreman grills - brilliant. Never bought one as I had too much kitchen stuff at the time, but I like to use my sister's and friends' when I go round for meals.
Slendertone - even with regular exercise and careful eating, this did nothing but shock me. Fail.
Some cooking pot thing that allegedly allowed you to cook everything in one pot (e.g. pasta bakes, whole roast chicken, cornbread, chocolate sponge...) - it didn't cook anything... at all! I wrote an angry letter of complaint accusing them of false advertising and got a full refund, shipping and all.
Rotating spice holder - very handy, I still use it now 6 years later.
I'm sure there's been more... lol