Which is the most annoying song you have ever heard?

I really, really despise California Girls by Katy Perry. Because the first time I heard it, my friend was saying " you have to listen to this song it's so great and it's called california girls!" I thought it was the Beach Boys song, and it turned out to be Katy Perry. Huge disappointment... It doesn't help she adores it and introduced it to a different friend who also adores it. So now they sing it all the time, and I have had that song stuck in my head for ages. It's not the most annoying song I've ever heard, but just because of all the times I've had to hear it, I hate it and start screaming whenever it comes on.