What's your least-favorite genre, and why?
Romance. It just really doesn't interest me as a plot - it can be a great character device, but if the characters are doing nothing but being in love (or trying to deny the fact they're in love, or angsting over whether they love somebody else more), I'm generally just not interested unless the characters are particularly fascinating in themselves.
I am also not fond of whatever one might call the genre of books revolving around the life of poor dysfunctional Icelandic families during the twentieth century. Unfortunately this includes about two thirds of all Icelandic fiction published (the rest is almost exclusively children's books and the mystery novels written by some two or three authors). They just... usually aren't entertaining except maybe in some stray scenes here and there, the characters never seem to be remotely likable, and they never seem to use any of the potential there could be for making the story interesting. I just don't get them. :/ Sure, they can provide a vivid commentary on the conditions of working-class families in small fishing villages in Iceland in the early twentieth century, but... as far as I can tell they're just generally no good as stories.