Most annoying character

The Fireflies are annoying in how evil they are with no redeeming qualities, and the Sheriff got on my nerves toward the end when he put his vengeance above everything. He had the chance to stop them but he kept dragging it out too long, giving them a chance to escape. By that point I didn't even feel bad for him when he got killed.

The red headed guy and the older lady in the hotel.

Baby, by a long shot! Although not as annoying as she was in House of 1000 Corpses.