Lemsips and other medicated drinks.
What is the point of them? Why not just have two paracetamol and then have a drink that actually tastes nice?
Loan companies who advertise on daytime TV.
My uncle and aunt have (fairly obvious) learning difficulties and have managed to take out loans with various companies despite the fact they have absolutely no means to pay them back and no way could understand the small print. They now have thousands of pounds worth of debt and should never have been given the loans in the first place, but they have absolutely no means of fighting their own corner. Luckily for them they have my dad who is well educated and looks the part (i.e. wears expensive suits) and has managed to organise a realistic payment plan for them although the loans should never ever have been approved. Awful to think of how many people in that situation don't have someone to fight their corner against these shameful organisations. People were banging on their door for the money and they were terrified.
Personalised number plates.
Most of them are really crap. Okay, I might keep the best ones but I pity the fool who pays good money for something that takes me about 10 minutes to try and decipher what it might be supposed to say. And that's 10 minutes I won't get back again.
Bananas.
I just don't like them. I never have, I never will. People insist on eating them around me and they smell. I get excited about delicious smoothies and then suffer the crushing disappointment of realising it just tastes of banana. Even though it's red. And it even rears its ugly head in puddings when I least expect it. The world would be a better place without bananas.