Least Favorite Genre

Is there a genre of books that you least like? For me, it's romance. I don't know why, but I don't enjoy romance at all, unless it's one of the many genres within a single book. Romance for me has always been too idealized. I don't like mainsteam literature, either. That's what they make you read in school, and you have to analyze it and write essays about them.
My least favorite genre is probably horror/scary books. I just have never liked them. I love the romance though! I agree it is idealized, but that is part of the reason I like it.
I happen to love horror novels. For me, horror will combine one or two realistic things and make them seem even more real. I like horror because so much of it relies on the reader's imagination and fears.