I'll start.
Shark vacuum cleaner.
I should have got another Miele. The Shark is just another average sucker upper.
A Dualit toaster.
After years of cheap toasters that starts off great but soon end up toasting one side more than the other, I listened to the years of recommendations on MN and spend £140 on an effing Dualit toaster just for it to do exactly what allllllll the other toasters do. The only difference is, is that it looks a tiny bit better and as though I have stupid money to throw at ridiculous items like toasters. Never again.
Anyone else?
What other things are always recommended by other Mumsnetters that actually turn out to be a bit shit?