Food packets that have a little "peel here" sign, but they either don't peel at all, or just rip in a haphazard manner.
Public toilets where the roll of toilet paper is packed so tightly into the reel, that when you pull on the end, the roller doesn't roll, and you just get a piece of paper that's the size of a postage stamp.
Trying to read news articles on my phone - firstly, the delay whilst the "consent to cookies" loads up, then the endless adverts and links to other news stories, peppered throughout the piece you're trying to read, which just bombards the senses and makes me give up.
Agree with PP about people just walking behind my car when I'm reversing. I don't have sensors to warn me. It's like a life or death game.
The Postman who slams the garden gate loudly on the way in and out, and bangs the door 100 times louder than is necessary - cue excessive barking. And my DH works nights, so is trying to sleep.
TV channels that want you to register and sign in - why?
Companies like Wowcher, who don't appear to employ anyone who will actually have a conversation with a customer. Messages just go round in circles until the end of time.