I use a spin-off of the plastic sled; it's called a "Deer Sleigher". I got it through Cabela's years ago. It's a piece of heavyweight plastic that you can roll up and carry in a backpack or packframe. It has holes in the sides to "lace" the deer in place, and a grometted hole in the front that you put the drag rope through and around the deer's head. When you start pulling, the front curls up just like a toboggan. I also insert my UNLOADED rifle under the laced up deer so I don't have to carry it (also any extra outer clothing I don't want to wear).
I thought about the plastic sled, but didn't want to be walking around carrying a sled all day.
This thing works really well, even on dry ground. On snow, you hardly even know you're pulling anything. Only thing is, you have to get used to hunting with a pack on your back.