Anything that advertises something that I don't need.
This however is one of the funniest and effective that I have ever seen. Even if i don't want the product! Perfectly encaptures Boris "cow" Johnson [video="youtube;NopeeBmjwEo"]http://www.youtube.com/watch?v=NopeeBmjwEo[/video]
Any advert with annoying children/families e.g. Haribo, and whatever that chicken thing is where the girl says 'Good job Emily' to the egg. Seriously, what the HELL is that?!
That Greek yoghurt advert annoys the **** outta me as well. The 'It's not a myth!' one.. That woman's voice, she does the Three advert as well. I think it's Sophie from Peep Show