Adam Levine, Louis Tomlinson, Taylor Swift, Kesha and Carly Rae.

She's always one of the most mentioned in a thread like this.

I came in here to say just that. I can't stand his voice. And the whole of Emblem3

Jesse J
Charlie in Fancy and BBC
JB
Britney in isbe and a lot of FF
Bey
Adam in pay phone
Pharrell count?
Shakira when too nasal and feline
Spongebob
Ellie in the Calvin song
Icona pop
Angelica Pickles/myah Marie
Calvin Harris
Cher loyd

Demi. Skyscraper is probably the most annoying song I've ever heard.

And I used to think Ariana had a nice voice, but it's becoming more and more annoying it seems. She has very little control in her voice, and nowadays she just screeches and belts through everything (see Bang Bang)

Lady Gaga and Madonna