I'll support what a number of posters have mentioned:
1) green bean casserole: I could never stomach that canned cream of mushroom stuff, and the waterlogged canned green beans didn't help
2) sweet potato casserole with mini marshmallows: I love sweet potatoes baked and served plain, but the addition of sugary stuff, no thank you
3) oh Jennifer, you and me both...the thought of that fruit cocktail/whipped topping/marshmallow concoction (I think we called it ambrosia) makes me nauseous to this day, but Mom loved it, so it was a regular on the holiday table
4) pumpkin pie: the whole thing just isn't very appetizing to me...the brown color combined with the custard-like consistency...I'll pass, thank you.
Basically, Thanksgiving dinner for me is just a stop on the road to what I really want and like: the sandwiches made with white bread, stuffing, turkey, mayo, and pepper!