I don't mind Taylor Swift. Red is actually a pretty enjoyable album. I enjoyed it enough to pick up the vinyl pressing, at least. It was cheap, there are more than a few good songs, and it's actually a gatefold, unlike a lot of more expensive 2xLPs out there. The entire presentation is pretty slick.
I'm struggling to think of any artists that I hate. I try not to linger on that and I hardly ever listen to the radio so I have the advantage of not being exposed to the same songs over and over again.
I don't like the obsession with The Beatles that a lot of people display, as though it is some amazing accomplishment to enjoy music from previous decades (see the typical YouTube comment "I am 13 and listen to this. My generation listens to crappy music. I am cool because of The Beatles" or "Thump up if you're listening in 2013"). I have nothing against The Beatles, they're just overrated.
Also, The Black Eyed Peas can be really annoying.