Holy Taco lists the 7 most annoying people at Thanksgiving dinner. My favorite? "The Person With The Secret Everyone Already Knows."
Here's the description:
You'll know this person is coming to your thanksgiving about three and a half minutes before they get there, because you're mother will pull you aside and say, "Ben is coming. Now, he's gay, but he hasn't come out to the family yet, so don't say anything about gay things. Everyone, did you hear that? Ben is coming and he's gay, but he hasn't come out yet!"
My addition to the list would be the family member known for inescapable conversations. Or maybe that one weird person who eats with your relatives every holiday, but still not quite sure how he or she is related to you.
Who annoys you most on Thanksgiving?