It's a little late to get one for this ugly Christmas, but keep this sweater customizer by Ugly Christmas Sweater in mind for all your future ugly holiday needs.
You start by picking out the sweater's color. You have 10 choices ranging from hot pink to black. Then you pick the overall pattern which is mostly trees and snowflakes. After that is when you can add your own creative (and hopefully subversive) touch.
The cost? $67.95 plus shipping.