Black dress is my vote based on this picture. Nice figure and great legs in heels. But I'd be willing to reconsider if we could remove the dresses and take another look ....
do you even have to ask? black dress has the perfect hourglass figure. big boobs, nice hips, and a small waist. silver is thick without being bless with flattering curves. she should not be wearing a dress that tight for a girl of her size and shape but there are people who like chubby girls.
Black dress looks like it here but easily see the chick in the silver dress having a very nice body without that bad dress on.
Looking at her arms and around her shoulders she looks like she might not be as chubby as the dress makes her look....her legs look like they might be nice too.
Bottom line, post better pics of her....unless this is part of the exercise...