It's funny, as some of you have mentioned, there is stuff I used to hate, genres even, that I now have grown to enjoy. I was, in my formative years a metal head and would not entertain anything else that didn't have thrashing guitars. As I've grown more maturer than wot I was, my taste has mellowed, or at least widened and I can now include Bluegrass, reggae, country, rap, classical and even opera as favourites. I don't think there is one genre that I could say I hate. Maybe jazz, but I like some jazz, so not completely. Jazz funk is a bit of a no no for me, but it's just certain songs that irk me.
There's some good ones listed that I had forgotten about. Rod Stewart is a particular hate of mine that I had probably hidden in some dark corner of my mind, locked safely away until someone mentioned him