Ever since my experience listening to it lately, 7/11 by Beyonce is just nothing but a huge joke. Her voice sounds so annoying there, in fact very eerily similar to Azealia Banks, who I thought already had one of the most annoying vocals in music already.
Also, a lot of hits where major pop stars collaborate with rappers. A lot of songs following this formula fall flat for me very badly, and there's some that are this taken up to an even worse notch, such as Hall Of Fame by The Script. The lyrics were good, but the reason why it sucked for me was the fact they did a pointless collab with will.i.am (aka that annoying guy from Black Eyed Peas) for it, and it ruins the song because he doesn't blend in with it, and as a result I would have tolerated it more if he wasn't there.
And any songs that sound like a genre that doesn't suit the artist, such as the example with Beyonce I mentioned earlier, but the most jarring for me was Shake It Off by Taylor Swift. I really hate that she changed her genre from her old country-pop sound to full-on generic pop, and it doesn't help that Shake It Off is getting overplayed a lot right now.
And speaking of overplayed crap, Crazy by Gnarls Barkley and Hey Ya! by Outkast are two songs that were spammed so much I never want to hear them again. They were very intolerable songs for me.